Glossary - Technical Terms - English

    µA. MicroampereOne-millionth of an ampere (10-6).
    Abrasion ResistanceAbility of a wire, cable or material to resist surface wear.
    AbsorptionPhysical phenomenon that attenuates light traveling in fibers by converting it into heat, thereby raising the fiber’s temperature. Absorption results from impurities and defects in the glass structure.
    ACAlternating Current. Current in which the charge-flow periodically reverses and is represented by 1 = 1 º cos (2 f + f) where, 1 is the current, 1 º is the amplitude, (f) the frequency, (f) the phase angle.
    AC Alternating Current (AC)Current in which the charge-flow periodically reverses.
    AC ResistanceThe total resistance offered by a device in an alternating current circuit due to inductive and capacitive effects, as well as the direct current resistance .
    Accelerated AgingA test in which voltage, temperature, etc., are increased above normal operating values to obtain observable deterioration in a relatively short period of time. The plotted results give expected service life under normal conditions.
    AcceleratorA chemical additive which hastens a chemical reaction under specific conditions.
    Acceptance AngleThe half-angle of the cone within which all incident light is totally internally reflected by the fiber core. For graded index fibers, acceptance angle is a function of position on the entrance face of the core.
    ACMAluminum conductor material.
    ActivatorA chemical additive used to initiate the chemical reaction in a specific chemical mixture .
    Active CurrentIn an alternating current, a component in phase with the voltage. The working component as distinguished from the idle or wattless component.
    Active PressureIn an AC circuit, the pressure which produces a current, as distinguished from the voltage impressed upon the circuit.
    AdapterA device that enables any or all of the following a) different sizes or types of plugs to mate with one another or to fit into a telecommunications outlet/connector; b) the rearrangement of leads; c) large cables with numerous wires to fan out into smalle
    Adapter-FiberA mechanical media termination device designed to align and join fiber optic connectors. Often referred to as a coupling, bulkhead, or interconnect sleeve.
    AdhesionThe state in which two surfaces are held together by interfacial forces which may be chemical or mechanical in nature .
    Adhesive BondedCables bonded by adding an adhesive coating to the surface of the cable components, then joining and curing the adhesive to form a cable. See Bonded Cables.
    Adjacent ConductorAny conductor next to another conductor either in the same multi-conductor cable layer or in adjacent layers.
    AdministrationThe method for labeling, identification, documentation and usage needed to implement moves, additions and changes of the telecommunications infrastructure.
    AdmittanceThe measure of the ease with which an alternating current flows in a circuit. The reciprocal of impedance.
    AEICAssociation of Edison Illuminating Companies
    Aerial CableA cable suspended in the air on poles or other overhead structure
    AgingThe change in properties of a material with time under specific conditions.
    AlloyA combination of two or more metals to form a new or different metal having specific or desirable qualities.
    All-Rubber CableA cable in which all interstices between conductors are filled with rubber compound.
    Alternating Current (AC)Electric current that continually reverses its direction. It is expressed in cycles per second (hertz or Hz).
    Alternating VoltageThe voltage developed a cross a resistance or impedance through which alternating current is flowing.
    Aluminum ConductorAn aluminum wire or group of wires not suitably insulated to carry electrical current.
    Aluminum-Steel ConductorA composite conductor made up of a combination of aluminum and steel wires.
    Ambient TemperatureThe temperature of the medium surrounding an object. Generally a lower temperature than the temperature at which the cable is operating.
    American Wire Gauge (AWG)The standard system used for designating wire diameter. The lower the AWG number, the larger the diameter. Also called the Brown and Sharpe (B&S) wire gauges.
    AmpacityThe maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations. (Same as Current Carrying Capacity.)
    Ampere (AMP)The unit of cur rent. One ampere is the current flowing through one ohm of resistance at one volt potential.
    Ampere’s LawThe magnetic intensity at any point near a current carrying conductor can be computed on the assumption that each infinitesimal length of the conductor produces at the point of an infinitesimal magnetic density. The resulting magnetic intensity at the poi
    AmplitudeHeight of a waveform that represents signal strength.
    AnalogA signaling format that uses continuous physical variables such as voltage amplitude or frequency variations to transmit information.
    Analog SignalA signal in which the intelligence is represented by continuously varying quantities.
    Angle of IncidenceThe angle between an incident ray and the normal to a reflecting surface.
    Angle of RefractionAngle formed between a refracted ray and the normal to the surface. This angle lies in a common plane with the angle of incidence.
    Anneal (Soften)To subject to high heat with subsequent cooling. When annealing copper, the act of softening the metal by means of heat to render it less brittle.
    Annular ConductorA number of wires stranded in three reversed concentric layers around a core.
    AnodeThe electrode through which a direct current enters the liquid, gas or other discrete part of an electrical circuit; the positively charged pole of an electro-chemical cell.
    ANSIThe American National Standards Institute.
    Anti-OxidantA substance which prevents or slows down oxygen decomposition (oxidation) of a material exposed to air.
    Anti-OzonantA substance which prevents or slows down material degradation due to ozone reaction.
    Appliance Wire and CableAppliance wiring material is a classification of Underwriters’ Laboratories, Inc., covering insulated wire and cable intended for internal wiring of appliances and equipment. Each construction satisfies the requirements for use in particular applications.
    Aramid YarnStrength elements that provide tensile strength, support, and additional protection of fiber bundles. It is commonly referred to as Kevlar (a DuPont trademark).
    Arc ResistanceThe time required for an arc to establish a conductive path in a material.
    Area of ConductorThe size of a conductor cross-section, measured in circular mils, square inches, etc.
    ArmorA braid or wrapping of metal, usually steel or aluminum, used for additional mechanical protection in harsh environments.
    AttenuationThe decrease in magnitude of the power of a signal in transmission between points. Attenuation is usually measured in decibels per unit length at a specific frequency.
    Attenuation to Crosstalk Ratio (ACR)The difference between attenuation and crosstalk, measured in dB, at a given frequency. Important characteristic in networking transmission to assure that signal sent down a twisted pair is stronger at the receiving end, after being attenuated, than are a
    Audio FrequencyThe range of frequencies audible to the human ear. Usually 20-20,000 Hz.
    AWGAbbreviation for American Wire Gauge.
    B & S GaugeThe same as American Wire Gauge (AWG).
    Balanced CircuitA circuit so arranged that the impressed voltages on each conductor of the pair are equal in magnitude but opposite in polarity with respect to ground.
    Balanced LineA cable having two identical conductors which carry voltages opposite in polarity and equal in magnitude with respect to ground.
    Band MarkingRepeated circumferential bands applied to a conductor at regular intervals for identification.
    Banded CableTwo or more cables banded together by stainless steel strapping.
    BandmarkingA circumferential color band applied to an insulated conductor at regular intervals for identification.
    Bandwidth(1) The difference between the upper and lower limits of a given band of frequencies. Expressed in Hertz. (2) A measure of the maximum frequency range over which light intensity exiting a waveguide one kilometer in length can be varied before the attenua
    Bank WireAn insulated wire used for the interconnection of selector switches in automatic telephone exchanges.
    Bare ConductorA conductor not covered with insulating material.
    Barrel-PackedMethod of coiling into a fiber drum for shipment.
    BasebandIn data transmission, the use of a dedicated end-to-end connection to carry a single channel only.
    Baseband SignalingTransmission of a digital or analog signal at its original frequencies, i.e., a signal in its original form, not changed by modulation.
    Basic Conductor LoadThe limiting conductor-load per unit length assumed for the purposes of design.
    Battery CableA single conductor cable, insulated or uninsulated, used for carrying current from batteries to the point power is needed.
    BeddingA layer of material applied to a cable immediately below the armoring.
    BeltNumber of layers of insulation on a conductor, or number of layers of jacket on a cable.
    Belted-Type CableMultiple conductor cable having a layer of insulation over the assembled insulated conductors.
    Bend LossA form of increased attenuation caused by (a) having an optical fiber curved around a restrictive radius of curvature or (b) microbends caused by minute distortions in the fiber imposed by externally induced forces.
    Bend RadiusRadius of curvature that a fiber optic or metallic cable can bend without any adverse effects.
    BifilarA winding made non-inductive by winding together (as one wire) two wires carrying current in opposite directions.
    Bimetallic WireA wire formed of two different metals joined together (not alloyed). It can include wire with a steel core clad wire, or plated or coated wire.
    BinderA spirally served tape or thread used for holding assembled cable components in place awaiting subsequent manufacturing operations .
    Binding PostA device for clamping or holding electrical conductors in a rigid position.
    BitOne binary (0 or 1) digit.
    Bond StrengthAmount of adhesion between bonded surfaces, e.g. in cemented ribbon cable.
    Bondable WireAn insulated wire treated to facilitate adherence to materials such as potting compounds. Also, magnet wires used in making coils when bonding the turns together is desired .
    Bonded CableCable consisting of pre-insulated conductors or multi-conductor components laid-in parallel and bonded into a flat cable. See Solvent-Bonded, Adhesive-Bonded and Film Bonded.
    Bonded ConstructionAn insulation construction in which the glass braid and nylon jacket a re bonded together.
    Bonded Flat CableFlat cable consisting of individually insulated conductors lying parallel and bonded together: application in electronics, telecommunications or computers.
    BondingThe permanent joining of metallic parts to form an electrically conductive path that will assure electrical continuity and the capacity to conduct safely any current likely to be imposed on it.
    Bonding ConductorAn insulated or uninsulated conductor forming part of the cable assembly which is used for the purpose of connecting non-current carrying parts of electrical equipment to a system grounding conductor.
    BoosterA device inserted into a line (or cable) to increase the voltage.
    Boot(1) Protective covering over a cable, wire or connector in addition to the normal jacketing or insulation. (2) A form placed around wire termination of a multiple-contact connector to contain the liquid potting compound before it hardens.
    BPFBillion paired feet.
    BraidA fibrous or metallic group of filaments interwoven in cylindrical form to form a covering over one or more wires.
    Braid AngleThe smaller of the two angles formed by the shielding strand and in the axis of the cable being shielded.
    Braid CarrierA spool or bobbin on a braider that holds one group of strands or filaments consisting of a specific number of ends. The carrier revolves during braiding operations.
    Braid EndsThe number of strands used to make up one carrier. The strands are wound side-by-side on the carrier bobbin and lie parallel in the finished braid.
    Braiding MachineMachine used to apply braids to wire and cable and to produce braided sleeving and braids for tying or lacing purposes. Braiding machines are identified by the number of carriers.
    Brake WireWire used in mobile-home, travel and truck trailers to supply current to the electrical braking system.
    Breakdown (Puncture)A disruptive discharge through the insulation.
    Breakdown of InsulationFailure of an insulation resulting in a flow of current through the insulation. It may be caused by the application of too high voltage or by defects or decay.
    Breakdown VoltageThe voltage at which the insulation between two conductors breaks down.
    BreakoutThe point at which a conductor or group of conductors breaks out from a multi-conductor cable to complete circuits at various points along the main cable.
    Breakout CableMulti-fiber cable constructed in the tight buffered design with individually jacketed fibers. Designed for ease of connectorization and rugged applications for intra- or inter-building requirements.
    BridgeA device used to expand a local area network by forwarding frames between data link layers.
    Bridged TapThe multiple appearances of the same cable pair at several distribution points.
    BroadbandIn data transmission, the use of a carrier signal, rather than direct modulation, to carry several simultaneous channels.
    BufferCoating used to protect optical fiber from physical damage. Types include tight buffer (indoor) or loose tube (outdoor).
    Building Entrance AreaA space in which the joining of inter- or intra-building telecommunications backbone facilities takes place. An entrance room may also serve as an equipment room.
    Building WireWire used for light and power in permanent installations utilizing 600 volts or less. Usually in an enclosure and which will not be exposed to outdoor environments .
    Bunch StrandAny number of conductor strands twisted together in one direction with the same lay length.
    Bunched StrandingA group of strands twisted together in a random manner and the same direction without regard to geometric arrangement of specific strands.
    BuncherA machine that twists wires together in random arrangement.
    BundleSeveral individual fibers contained within a single jacket or buffer tube. Also a group of buffered fibers distinguished in some fashion from another group in the same cable core.
    Buried CableA cable installed directly in the earth without use of underground round conduit. Also called Direct Burial Cable.
    Buried Distribution and Service WiresTelephone wires which are designed to provide buried service extensions from distribution cables to the subscriber’s protector.
    BusWire used to connect two terminals inside of an electrical unit.
    BushingA mechanical device used as a lining for an opening to prevent abrasion to wire and cable.
    Butyl RubberA synthetic rubber with good insulating properties (i.e. low voltage cords).
    ByteTypically a group of eight binary digits.
    C.S.A.An abbreviation for the Canadian Standard’s Association. (The Canadian counterpart of Underwriters’ Laboratories.)
    CableA stranded conductor with or without insulation and other coverings (single-conductor cable) or a combination of conductors (multiple-conductor cable). In fiber optics, a jacketed fiber or jacketed bundle in a form which can be terminated.
    Cable AssemblyTypically, the cable and associated connectors that is ready to install.
    Cable Bend RadiusThe radius that a fiber can be bent before risking increased attenuation or fiber breaks.
    Cable ClampA device used to give mechanical support to the wire bundle or cable at the rear of a plug or receptacle.
    Cable Clamp AdapterA mechanical adapter that attaches to the rear of a plug or receptacle to allow the attachment of a cable clamp.
    Cable CoreThe portion of an insulated cable lying under a protective covering.
    Cable Core BinderA wrapping of tapes or cords around the conductors of a multiple-conductor cable used to hold them together.
    Cable FillerThe material used in multiple conductor cables to occupy the spaces formed by the assembly of components forming a core of the desired shape (normally cylindrical).
    Cable RackThe vertical or horizontal open support (usually made of aluminum or steel) that is attached to a ceiling or wall.
    Cable SheathThe overall protective covering applied to cables.
    Cable TrayA ladder, trough, solid-bottom or channel raceway system intended for, but not limited to, the support of telecommunications media (i.e., cable).
    Cable VulcanizerCompression molding machine used to repair cable jacketing that has had a part removed for splicing, for adding connectors or other devices or for replacing damaged sections.
    Cable, Star QuadA multi-core radio or television relay cable in which the conductors are arranged in quads and each quad consists of four conductors twisted together, the diagonally opposite conductors constituting a pair circuit. Also known as spiral four cable.
    Cable-in-DuctSystem for direct burial in which a flexible conduit is extruded over electrical cables for a single pre-assembled unit.
    Cabling(1) A combination of all cables, wire, cords and connecting hardware; (2) Twisting together two or more insulated conductors by machine to form a cable. In fiber optics, a method by which a group or bundle of fibers is mechanically assembled.
    Cabling FactorUsed in the formula for calculating the diameter of an unshielded, unjacketed cable. D = Kd, where D is the cable diameter. K is the factor and d is the diameter of one insulated conductor.
    CapacitanceThe ratio of the electrostatic charge on a conductor to the potential difference between the conductors required to maintain that charge. Units expressed in Farads.
    Capacitance UnbalanceThe inequalities of the capacitances of the wires of a telephone circuit to other wires or to earth which will produce interference. Various forms of unbalance arise according to the circuits concerned in the measurement,
    hence side-to-side, pair-to-pair
    Capacitance Unbalance to GroundAn inequality of capacitance between the g round capacitance of the conductors of a pair which results in a pickup of external source energy, usually from power transmission lines.
    Capacitance, DirectThe capacitance measured directly with all other conductors, including shield, short circuited to ground.
    Capacitance, MutualThe capacitance between two conductors with all other conductors, including shield, short circuited to ground.
    Capacitive CouplingElectrical interaction between two conductors caused by the capacitance between them.
    Capacitive Reactance (Xc)The opposition to alternating current due to the capacitance of the cable or circuit. Measured in ohms.
    Capillary ActionThe phenomenon of liquid rising in a small interstice due to surface tension.
    CarrierThe woven element of a braid consisting of one or more ends (strands) which creates the interlaced effect. Also, a spindle, spool, tube, or bobbin (on a braiding machine) containing yarn or wire, employed as a braid.
    CATVAcronym for Community Antenna Television.
    CCTVAcronym for Closed-Circuit Television.
    CEBECBelgium Approval Agency; Comite Electrotechnique Belge Service de la Marque.
    CEEEuropean Standards Agency; International Commission on Rules for the Approval of Electrical Equipment.
    Cellular PlasticsExpanded or foam, consists of individual closed cells of inert gas suspended in a plastic medium, resulting in a desirable reduction of the dielectric constant.
    CENELECEuropean Standards Agency; European Committee for Electrotechnical Norms.
    Central MemberA material located in the middle of a cable that provides extra strength and anti-buckling properties.
    Central OfficeThe place where communications common carriers terminate customer lines and locate switching equipment that interconnects those lines.
    Certificate of Compliance (C of C)A written statement; normally generated by a Quality Control Department, which states that the product being shipped meets customer’s specifications.
    Certified Test Report (CTR)A report providing actual test data on a cable. Tests are normally conducted by the Quality Control Department to confirm that the product being shipped conforms to specifications.
    Changing CurrentThe current produced when a D.C. voltage is first applied to conductors of an unterminated cable. It is caused by the capacitive reactance of the cable, and decreases exponentially with time.
    Characteristic ImpedanceThe impedance that, when connected to the output terminals of a transmission line of any length, makes the line appear infinitely long. The ratio of voltage to current at every point along a transmission line on which there are no standing waves.
    ChargeThe quantity of electricity held statically in a condenser or an insulated conductor.
    Chlorinated Polyethylene (CPE)A polymerized ethylene resin that has been treated or combined with chlorine or a chlorine compound.
    Chlorosulfonated Polyethylene (CSPE)A rubbery polymer used for insulations and jackets. Manufactured by Dupont under the tradename of Hypalon.
    Chromatic DispersionSpreading of a light pulse caused by the difference in refractive indices at different lengths.
    CircuitA complete path over which electrons can flow from the negative terminals of a voltage source through parts and wires to the positive terminals of the same voltage source. When the continuity of the circuit is broken it is called an open circuit: when con
    Circuit SizesA popular term for building wire sizes 14 through 10 AWG .
    Circular Mil (cmil)A measurement used for the are a of wire, calculated by squaring the diameter. 1 circular mil = (.001) 2 x 10 6
    CladdingA method of applying a layer of metal over another metal where the junction of the two metals is continuously welded. In fiber optics, a sheathing intimately in contact with the core of a higher refractive index material which serves to provide optical i
    Clorosulfonated Polyethylene (CSPE)A rubbery polymer used for insulations and jackets. Manufactured by DuPont under the trade name of Hypalon.
    Closed End SpliceAn insulated splice in which two or more wires overlap and enter the splice from the same end of the barrel.
    Closet, TelecommunicationsAn enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling. The closet is the recognized location of the cross-connect between the backbone and horizontal facilities.
    CoatingA material applied to the surface of a conductor to prevent environmental deterioration, facilitate soldering or improve electrical performance.
    Coaxial CableA cable consisting of two cylindrical conductors with a common axis, separated by a dielectric.
    Coaxial ConnectorA connector that has a coaxial construction and is used with coaxial cable.
    Coherent SourceA light source which emits a very narrow, unidirectional beam of light of one wavelength (monochromatic).
    Coil EffectThe inductive effect exhibited by a spiral-wrapped shield, especially above audio frequencies.
    Cold BendA laboratory test procedure whereby a sample of wire or cable is wound around a mandrel of a specified size at a specified temperature for a given number of turns at a given rate of speed and examined for defects.
    Cold FlowPermanent deformation of the insulation due to mechanical force of pressure (not due to heat softening).
    Cold JointA soldered joint made with insufficient heat.
    Cold TestAny test to determine the performance of cables during or after subjection to a specified low temperature for a specified time.
    Cold WorkThe hardening and embrittlement of a metal by repeated flexing action.
    Color CodeA color system for circuit identification by use of solid colors, tracers, braids, surface printing, etc.
    Commercial BuildingA building or portion thereof, that is intended for office use.
    Common Axis CablingIn multiple cable constructions, a twisting of all conductors about a common axis with two conductor groups then selected as pairs. This practice yields smaller diameter constructions than does a separate axis construction, but tends to yield greater sus
    Compact ConductorStranded conductor rolled to deform the round wires to fill the normal interstices between the wires in a strand.
    CompatibilityThe ability of dissimilar materials to exist in mutual proximity or contact without changing their physical or electrical properties.
    Composite (Clad) WireA wire having a core of one metal with a fused outer shell of different metals.
    Composite CableA cable containing more than one type or gauge size of conductors (I.e. power and control conductors in one assembly).
    Composite ConductorTwo or more strands of different metals assembled and operated in parallel.
    CompoundAn insulating or jacketing material made by mixing two or more ingredients.
    Compression CableA pipe type cable in which the pressure medium is separated from the insulation by a membrane or sheath.
    ConcentricA central core surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement.
    Concentric StrandA strand that consists of a central wire or core surrounded by one or more layers of spirally laid wires.
    Concentric Stranded ConductorsManufactured to ASTM, ICEA, and CSA standards. The most common fixed installation type conductors are : 1) Round-no diameter reduction: 2) Compressed-approximately 3% diameter reduction; 3) Compact-approximately 10% diameter reduction.
    Concentric StrandingA group of uninsulated wires twisted so as to contain a center core with one or more distinct layers of spirally wrapped, uninsulated wires laid overall to form a single conductor.
    ConcentricityIn a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of the circular insulation.
    Concentric-Lay CableA concentric-lay conductor, or a multiple-conductor cable composed of a central core surrounded by one or more layers of helically laid insulated conductors.
    ConductanceThe ability of a conductor to carry and electric charge. The ratio of the current flow to the potential difference causing the flow. The reciprocal of resistance.
    ConductivityThe capacity of a material to carry electrical current that is usually expressed as a percentage of copper conductivity (copper being 100%).
    ConductorA wire (or combination of wires not insulated from one another) suitable for carrying electric current.
    Conductor ShieldAn extrusion of black semi-conducting thermoses material over the conductor to provide a smooth interface with the insulation for even distribution of electrical stress.
    Conduit (Electrical Raceway)A rigid or flexible metallic or non-metallic raceway of circular cross section through which wire and cables can be pulled or housed.
    Connecting HardwareA device providing mechanical cable terminations.
    ConnectorA device used to physically and electrically connect two or more conductors. Also used to physically connect cable to equipment.
    Connector Return LossAmount of power reflected from the connector to connector interface, typically expressed in decibels.
    ContactThe part of a connector which actually carries the electrical current. Contacts are touched together or separated to control the flow of electricity.
    Contact Inspection HoleA hole in the cylindrical rear portion of contact used to check the depth to which a wire has been inserted.
    Contact SizeThe largest size wire which can be used with the specific contact. Also, the diameter of the engagement end of the pin.
    ContactsThe parts of a connector which actually carry the electrical current, and are touched together or separated to control the flow.
    Continuity CheckA test to determine whether electrical current flows continuously throughout the length of a single wire or individual wires in a cable.
    Continuous VulcanizationSimultaneous extrusion and vulcanization of rubber-like (thermoset) coating materials. Often referred to as CV.
    ContrahelicalCable spiraling in an opposite direction than the preceding layer within a wire or cable.
    Control CableA multi-conductor cable made for operation in control or signal circuits.
    Controlled Impedance CablePackage of two or more insulated conductors where impedance measurements betweenrespective conductors are kept essentially constant throughout the entire length.
    CopolymerA compound resulting from the polymerization of two different monomers.
    Copper CladSteel with a coating of copper welded to it before drawing as opposed to copper-plated. Synonymous with Copperweld.
    CopperweldThe trade name of Flexo Wire Division (Copperweld Steel Corp.) for its copper-clad steel conductors.
    CordA small, very flexible insulated cable constructed to withstand mechanical abuse. (Note: There is no sharp dividing line with respect to size between a cord and a cable, but generally, a cord is considered to be a size No. 10 and smaller )
    Cord, TelecommunicationsA cable using stranded conductors for flexibility as in distribution cords or line cords. Line cords can also use tinsel conductors.
    CordsetPortable cords fitted with a wiring device at one or both ends.
    CoreIn cables, a component or assembly of components over which other materials are applied, such as additional components, shield, sheath, or armor. In fiber optics, the transparent glass or plastic section with a high refractive index through which the ligh
    Core EccentricityMeasure of the displacement of the center of the core relative to the cladding center.
    Core EllipticityMeasure of the non-roundness of the core.
    CoronaA discharge of electricity which appears around a conductor when the potential gradient at the surface of the conductor exceeds a certain value.
    Corona ResistanceThe time that the insulation will withstand a specified level of field-intensified ionization that does not result in the immediate complete breakdown of the insulation.
    CorrosionThe process or result of a material being eaten or worn away, usually by chemical reaction.
    Coupling EfficiencyEfficiency of optical power transfer between two components.
    Coupling LossSignal losses due to small differences in numerical aperture, core diameter, core concentricity, and tolerances in splicing connectors when two fibers are aligned. Also known as Splicing Loss and Transfer Loss.
    Coupling RingA device used on cylindrical connectors to lock plug and receptacle together.
    CoverageThe calculated percentage which defines the completeness with which a metal braid covers the underlying surface. The higher percentage of coverage, the greater the protection against external interference .
    CoveringTextile braid or jacket of rubber plastics, or other materials applied over wire and cable to provide mechanical protection and identification.
    CPEChlorinated polyethylene can be used as either a thermoplastic or thermoset. It is a tough chemical and oil-resistant material and makes an excellent jacket for industrial control cable. As a thermoset, it can be used as an oil-resistant cord jacket. Typi
    CreepThe dimensional change with time of a material under a mechanical load.
    CreepageThe conduction of electricity across the surface of a dielectric.
    Creepage PathThe path across the surface of a dielectric between two conductors.
    Creepage SurfaceAn insulating surface which provides physical separation as a form of insulation between two electrical conductors of different potential.
    CrimpThe act of compressing a connector barrel around a cable in order to make an electrical connection.
    Crimp TerminationConnection in which a metal sleeve is secured to a conductor by mechanically crimping the sleeve with pliers, presses or automated crimping machines.
    Critical AngleSmallest angle at which a meridional ray may be totally reflected within a fiber at the core-cladding interface.
    Cross-ConnectA facility enabling the termination of cable elements and their interconnection, and/or cross-connection, primarily by means of a patch cord or jumper.
    CrosslinkedInter-molecular bonds between long chain thermoplastic polymers by chemical or electron bombardment means. The properties of the resulting thermo-setting material are usually improved.
    Cross-Sectional AreaThe area of the cut surface of an object cut at right angles to the length of the object.
    CrosstalkUndesired electrical currents in conductors caused by electromagnetic or electrostatic coupling from other conductors or from external sources. Also, leakage of optical power from one optical conductor to another.
    CSPEInsulating and jacketing compound based on chlorosulfonated polyethylene. Also known as Hypalon (DuPont registered trademark).
    CureTo change the physical properties of a material by chemical reaction, by the action of heat and catalysts, alone or in combination, with or without pressure.
    Curing CycleThe time, temperature, and pressure required for curing.
    CurlThe degree to which a wire tends to form a circle after removal from a spool. An indication of the ability of the wire to be wrapped around posts in long runs.
    CurrentThe rate of transfer of electricity. Practical unit is the ampere which re presents the transfer of one coulomb per second. In a simple circuit, current (I) produced by a cell or electromotive force (E) when there is an external resistance (R) and intern
    Current Carrying Capacity (Ampacity)The maximum current an insulated conductor can safely carry without exceeding its insulation and jacket temperature limitations.
    Current PenetrationThe depth a current of a given frequency will penetrate into the surface of a conductor carrying the current
    Current, Alternating (AC)An electric current that periodically reverses direction of electron flow. The number of full cycles occurring in a given unit of time (one second) is called the frequency of the current.
    Current, Direct (DC)Electrical current whose electrons flow in one direction only; it may be constant or pulsating as long as their movement is in the same direction.
    Customer PremisesBuilding(s) with grounds and appurtenances (belongings) under the control of the customer.
    Cut-Through ResistanceThe ability of a material to withstand mechanical pressure, usually a sharp edge of prescribed radius, without separation.
    CVAbbreviation for continuous vulcanization.
    CycleThe complete sequence of alternation or reversal of the flow of an alternating electric current. (See Hertz.)
    D.C.Abbreviation for Direct Current.
    Decibel (dB)A unit to express differences of power level. Used to express power gain in amplifiers or power loss in passive circuits or cables.
    Delay LineA cable made to provide very low velocity of propagation with long electrical delay for transmitted signals.
    Demarcation PointA point where the operational control or ownership changes.
    DEMKOApproval agency of Denmark.
    Depth of CrimpThickness of the crimped portion of a connector measured between two opposite points on the crimped surface.
    Derating FactorA factor used to reduce the current carrying capacity of a wire when used in environments other than that for which the value was established.
    DetectorA device that picks up light from fiber and converts the information into an electrical signal.
    Device, As Related to a Work StationAn item such as a telephone, personal computer, or graphic or video terminal.
    Device, As Related to ProtectionA protector, a protector mount, a protector unit or a protectomodule.
    Dielectric1) Any insulating medium which intervenes between two conductors and permits electrostatic attraction and repulsion to take place across it; 2) A material having the property that energy required to establish an electric field is recoverable in whole or
    Dielectric AbsorptionThat property of an imperfect dielectric whereby there is an accumulation of electric charges within the body of the material when it is placed in an electric field.
    Dielectric BreakdownThe voltage at which a dielectric material is punctured, which is divisible by thickness to give dielectric strength.
    Dielectric Constant (K)The ratio of the capacitance of a condenser with dielectric between the electrodes to the capacitance when air is between the electrodes. Also called Permittivity and Specific Inductive Capacity (SIC).
    Dielectric LossPower dissipated in an insulating medium as the result of the friction caused by molecular motion when an AC Electric field is applied.
    Dielectric StrengthThe voltage which an insulation can withstand before breakdown occurs. Usually expressed as a voltage gradient (such as volts per mil).
    Dielectric TestA test in which a voltage higher than the rated voltage is applied for a specified time to determine the adequacy of the insulation under normal conditions. Sometimes called a “Hi-Pot” test (high potential).
    DiffractionPhenomenon that results when light passes by an opaque edge or through an opening, generating weaker secondary wavefronts. These secondary wavefronts interfere with the primary wavefronts as well as with each other to form various patterns.
    DigitalA data format that uses discrete or separate physical levels to contain information.
    Digital SignalA signal in which the data is represented by a series of discrete steps or pulses.
    Dip CoatingAn insulating coating applied to the conductor by passing the conductor through an applicator containing liquid insulating medium.
    Direct Burial CableA cable installed directly in the earth.
    Direct CapacitanceThe capacitance measured directly from conductor to conductor through a single insulating layer.
    Direct Current (DC)An electric current which flows in only one direction.
    Direct Current Resistance (DCR)The resistance offered by any circuit to the flow of direct current.
    Direction of LayThe lateral direction in which the strands of a conductor run over the top of the cable conductor as they recede from an observer looking along the axis of the conductor or cable. Also applies to twisted cable.
    Discrete WiringWire or wires having distinct identity and purpose.
    DispersionSpread of the signal delay in an optical waveguide. It consists of various components: modal dispersion, material dispersion, and waveguide dispersion. As a result of the dispersion, an optical waveguide acts as a low-pass filter for the transmitted signa
    Disruptive DischargeA sudden, large increase in current through an insulation medium due to the complete failure of the medium under the electrostatic stress.
    Dissipation FactorThe tangent of the loss angle of the insulating material. (Also referred to as loss tangent, tand and approximate power factor.)
    Distribution CableIn telecommunications and CATV systems, the transmission cable between the distribution amplifier and the drop wire .
    Distribution FrameA structure with terminations for connecting the permanent cabling of a facility in such a manner that interconnection or cross-connections may be readily made.
    Disturbed ConductorA conductor that receives energy generated by the field of another conductor or an external source such as a transformer.
    Drain WireThe uninsulated wire in contact with an electrostatic shield throughout its length, in an instrumentation or control cable, used to discharge unwanted signals. Also provides a means of terminating laminated shields. Sometimes used to describe the metalli
    Draw Feed StockRod or wire that is subsequently drawn to a smaller size.
    DrawingIn the manufacturing of wire, pulling the metal through a die or series of dies for reduction of diameter to a specified size.
    Drop CeilingA ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: False Ceiling, Suspended Ceiling.
    Drop WireA telephone cable, usually consisting of one insulated telephone pair, which is used to connect a subscribers premises to open wire lines on poles.
    Dual Coaxial CableTwo individually insulated conductors laid parallel or twisted and placed within an overall shield and sheath.
    Duct(1) A single enclosed raceway for wires or cables. Also Conduit, Raceway; (2) a single enclosed raceway for wires or cables usually used in soil or concrete, (3) an enclosure in which air is moved. Generally part of the HVAC system of a building.
    DuctileCapable of being drawn out or hammered thin, or of being flexed or bent without failure.
    DuplexReferring to a type of data transmission, either half or full. Half duplex permits only one-way communication. Full duplex allows simultaneous two-way transmission.
    Duplex Cable(1) A cable composed of two insulated single conductor cables twisted together. (2) A cable composed of two fibers typically 62.5/125 mm Multi-Mode, placed in parallel under a thermoplastic sheath.
    Duplex ParallelTypically used in the thermo-couple industry to denote two parallel conductors of dissimilar metals insulated in parallel without twist and jacketed. Commonly applied to thermo-couple grades and extension wires.
    DurometerA measure of hard n e s s .
    EA symbol for voltage. Usually used to represent direct voltage or the effective (root-mean-square) value of an alternating voltage.
    EarthBritish terminology for zero reference ground.
    EccentricityLike concentricity, a measure of the center of a conductor’s location with respect to the circular cross section of the insulation. Expressed as a percentage of displacement of one circle within the other.
    Eddy CurrentCirculating currents induced in conducting materials by varying magnetic fields.
    ElastomerA rubber or rubber-like material which will stretch repeatedly to 200 percent or more and return rapidly and with force to its approximate original shape.
    ElectrodeA conductor through which a current enters or leaves a nonmetallic conductor.
    ElectrolysisThe production of chemical changes by passage of current through an electrolyte.
    Electrolytic Tough PitchA term describing the method of raw copper preparation to ensure a good physical and electrical grade copper finished product containing less than 1/10 of 1% impurities. (ASTM B5.)
    ElectromagneticPertaining to the combined electric and magnetic fields associated with movements of electrons through conductors.
    Electromagnetic CouplingEnergy transfer by means of a varying magnetic field.
    Electromagnetic FieldA rapidly moving electric field and its associated moving magnetic field.
    Electromagnetic InductionThe production of a voltage in a coil due to a change in the number of magnetic lines of force (flux linkages) passing through the coil.
    Electromagnetic Interference (EMI)Flowing currents generate magnetic fields. Depending on the strength and proximity, these magnetic fields can induce unwanted current in
    nearby conductive media, negatively affecting signal transfer.
    Electromotive Force (E.M.F)Pressure or voltage. The force which causes current to flow in a circuit.
    Electronic Wire and CableA length of conductive or semiconductive material used in an electronic application.
    ElectrostaticPertaining to static electricity or electricity at rest. A constant intensity electric charge .
    Electrostatic ShieldA copper or laminated aluminum/mylar tape wrap around a signal or instrumentation circuit (pair, triad, etc.) to protect from the electric field radiated by a voltage source. The grounded shield intercepts static interference and carries it off to ground.
    Electro-TinnedElectrolytic process of tinning wire using pure tin.
    ElongationThe fractional increase in the length of a material stressed in tension.
    Elongation at BreakThe tensile strain in a test piece stretched to breaking point, the conditions being such that the stress is substantially uniform over the cross – section.
    EmbossingA marker identification by means of thermal indentation leaving raised lettering on the sheath material of cable.
    Emergency OverloadsLoads which occur when larger than normal currents are carried through a cable or wire over a short period of time.
    EMIAbbreviation for electromagnetic interference.
    Enameled WireA conductor with a baked-on enamel film insulation. In addition to magnet wire, enameled insulation is used on thermocouple type wires and other wires.
    End FinishQuality of the surface at an optic-fiber’s end, commonly described as mirror, mist, hackle, chipped, cracked, or specified by final grit size used in polishing.
    EndsIn braiding, the number of essentially parallel wires of threads on a carrier.
    EnergizeTo apply rated voltage to a circuit or device in order to activate.
    Entrance Facility, TelecommunicationsAn entrance to a building for both public and private network service cables (including antennae) including the entrance point at the building wall and continuing to the entrance room or space.
    Entrance Point, TelecommunicationsThe point of emergence of telecommunications conductors through an exterior wall, a concrete floor slab, or from a rigid metal conduit or intermediate metal conduit.
    Entrance Room or Space, TelecommunicationsA space in which the joining of inter- or intra-building telecommunications backbone facilities takes place. An entrance room may also serve as an equipment room.
    EPDMEthylene-propylene-dene monomer rubber. A material with good electrical insulating properties.
    EPREthylene-propylene copolymer rubber. A material with good electrical insulating properties.
    Equal Load SharingAn even distribution of current between the parallel cables in a power circuit.
    Equipment Room, TelecommunicationsA centralized space for telecommunications equipment that serves the occupants of the building. An equipment room is considered distinct from a telecommunications closet because of the nature of complexity or the equipment.
    Etched WireA process applied to fluoro plastic wire in which the wire is passed through a sodium bath to create a rough surface to allow epoxy resin to bond the fluoro plastic.
    EthernetA local area network (LAN) which uses the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) access method on a bus topography.
    Exit AngleThe angle between the output radiation vectors and the axis of the fiber or fiber bundle.
    External InterferenceThe effects of electrical waves or fields which cause sounds other than the desired signal; static.
    External WiringElectronic wiring which interconnects subsystems within the system.
    Extruded CableCable with conductors which a re uniformly insulated and formed by applying a homogeneous insulation material in a continuous extrusion process.
    ExtrusionThe process of continuously forcing a plastic or elastomer and a conductor core through a die, thereby applying a continuous coating of insulation or jacket to the core or conductor.
    FAAFederal Aviation Administration.
    False CeilingA ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: Drop Ceiling, Suspended Ceiling.
    FaradThe standard unit of capacitance. A one farad capacitor is one in which a one coulomb charge produces a one volt potential difference between the plates.
    Fatigue ResistanceResistance to metal crystallization which leads to conductors or wires breaking from flexing.
    FDDI (Fiber Distributed Data Interface)A standard for a 100 Mbs fiber optic area network.
    FeedbackEnergy that is extracted from a high-level point in a circuit and applied to a lower level. Positive feedback reduces the stability of a device and is used to increase the sensitivity or produce oscillation in a system. Negative feedback, also called inv
    Feeder CableIn telecommunication or CATV systems, the transmission cable from the head end (signal pickup) to the trunk amplifier. Also called a Trunk Cable.
    Feedthrough(1) A conductor that connects patterns on opposite sides of a PCB. Also called Interfacial Connection; (2) A connector or terminal block, usually having double-ended terminals which permit simple distribution and bussing of electrical circuits.
    Feed-Through InsulatorsInsulators that carry a metal conductor through the chassis while preventing the ‘hot’ lead from shorting to the ground chassis.
    FEPFluorinated ethylene propylene, a melt extrudable fluorocarbon resin. Teflon is a DuPont registered trademark.
    FerrousComposed of and/or containing iron. A ferrous metal exhibits magnetic characteristics (i.e. steel armor).
    FerruleA short tube used to make solderless connections to shielded or coaxial cable.
    FextFar end crosstalk.
    FIApproval agency of Finland; Electrical Inspectorate.
    FiberA single, separate optical transmission element characterized by core and cladding.
    Fiber ChannelA high speed point-to-point, ANSI Optical Communications Standard that supports data transfer rates up to 1,062.5 Mbs (1 Gps).
    Fiber CleavingControlled fracture of an optical fiber along a crystalline plane which results in a smooth surface.
    Fiber DispersionPulse spreading in a fiber caused by differing transit times of various modes.
    Fiber OpticsA lightwave or optical communications system in which electrical information is converted to light energy transmitted to another location through optical fibers, and is there converted back into electrical information.
    Fiber TubingA loose, crush-resistant cylinder applied over individual fibers to provide mechanical protection.
    FieldAn area of influence around a magnet or electric charge.
    Field CoilA suitable insulated winding to be mounted on a field pole to magnetize.
    FilamentFiber characterized by extreme length.
    Filled CableA telephone cable construction in which the cable core is filled with a material that will prevent moisture from entering or passing through the cable.
    Filler(1) A material used in the cable to fill large interstices between electrical components; (2) A substance, often inert, added to a compound to improve properties and/or decrease cost.
    FilmA thin plastic sheet.
    Fine Stranded WireStranded wire with component strands of 36 AWG or smaller.
    FirestopA material, device, or assembly of parts installed in a cable system in a fire-rated wall or floor to prevent passage of flame, smoke, or gasses through the rated barrier.
    Flame ResistanceThe ability of a material not to propagate flame once the heat source is removed.
    Flame RetardanceAbility of a material to p revent the spread of combustion by a low rate of travel so the flame will not be conveyed.
    FlammabilityThe measure of the material’s ability to support combustion.
    Flammability TestA test to determine the ability of a cable to resist ignition when placed near a source of heat or flame and to self-extinguish when removed from this source.
    FlashoverA disruptive discharge around or over the surface of a solid or liquid insulator.
    Flat BraidA woven braid of tinned copper strands rolled flat at time of manufacture to a specified width.
    Flat CableA cable with two smooth or corrugated but essentially flat surfaces.
    Flat ConductorA wire having a rectangular cross section as opposed to round or square conductors.
    Flat Conductor CableA cable with a plurality of flat conductors.
    Flat Under Carpet CableA cable containing one or more cores, each formed of a group of wires, the diameters of the wires being sufficiently small to afford flexibility.
    Flex LifeThe measurement of the ability of a conductor or cable to withstand repeated bending before breaking.
    FlexibilityThe ease with which a cable may be bent without sustaining damage.
    FlexibleThe quality of a cable or cable component which allows for bending under the influence of outside force, as opposed to limpness which is bending due to the cable’s own weight.
    Flexible CableA cable containing one or more cores, each formed of a group of wires, the diameters of the wires being sufficiently small to afford flexibility.
    FloatingReferring to a circuit which has no connection to ground.
    Flux(1) The lines of force which make up an electrostatic field; (2) The rate of flow of energy across or through a surface; (3) A substance used to promote or facilitate fusion .
    Foam Skin CableA cable utilizing a foamed polyolefin inner layer covered by a solid polyolefin skin as the conductor insulation.
    Foamed PlasticsPlastic insulations having a cellular structure.
    FoamskinPolyethylene foam insulation with polyethylene outerskin.
    FoilA thin, continuous sheet of metal.
    Free ConnectorA connector for attachment to the free end of a wire or cable.
    FrequencyThe number of cycles, now expressed as hertz, by an alternating current in one second. The hertz is equivalent to the older unit cycles per second.
    Frequency ResponseThe characteristic of a device denoting the range of frequencies over which it may be used effectively.
    FT1One of several CSA flame test designations for wires and cables which pass the C22.2 No. 0.3 test requirements. (Other designations include FT2, FT4, etc.)
    Funnel EntryFlared or widened entrance to a terminal or connector wire barrel.
    Fuse WireWire made from an alloy that melts at a relatively low temperature .
    Fused CoatingA metallic coating which has been melted and solidified, forming a metallurgical bond to the base material.
    Fused ConductorsIndividual strands of heavy tinned copper wire stranded together and then bonded together by induction heating.
    G round PotentialZero potential with respect to the ground or earth.
    GainThe increase of voltage, cur rent, or power over a standard or previous reading. Usually expressed in decibels.
    GalvanometerAn instrument for detecting or measuring small electrical current.
    Gang StripSimultaneous stripping of all conductors in a flat or ribbon cable.
    Gas Filled CableA self-contained pressure cable in which the pressure medium is an inert gas having access to the insulation.
    GaugeA term used to denote the physical size of a wire.
    GigaA numerical prefix denoting one billion (10 9 ).
    GigabitOne billion bits of information.
    Gigahertz (GHz)A unit of frequency equal to one billion hertz.
    GimmickA short length of wire soldered onto a circuit component and used as a small adjustable capacitor.
    Graded-IndexA type of optical fiber in which the refractive index of the core is in the form of a parabolic curve, decreasing toward the cladding. This type of fiber provides high bandwidth capabilities.
    Graded-Index FiberAn optical fiber core that has a non-uniform index of refraction. The core is composed on concentric rings of glass, which have refractive indices that decrease from the center axis. The refractive index is changed in a systematic way from the center to t
    Ground(1) An electrical term meaning to connect to the earth or other large conducting body to serve as an earth thus making a complete electrical circuit; ( 2) A wire intended to be used for grounding (also called grounding conductor).
    Ground ConductorA conductor in a transmission cable or line that is grounded.
    Ground InsulationThe insulation used between a winding and the magnetic core or other structural parts, usually at ground potential.
    Ground LoopThe generation of undesirable current flow within a ground conductor, owing to the circulation currents which originate from a second source of voltage.
    Ground PlaneExpanded copper mesh which is laminated into some flat cable constructions as a shield.
    Ground PotentialZero potential with respect to the ground or earth.
    Ground Power CableA cable assembly fitted with appropriate terminations to supply power to an aircraft from ground power unit.
    HalogenA term used to identify any of the four elements chlorine, fluorine, bromine and iodine, grouped together because their chemical properties are similar.
    Hard Drawn Copper WireCopper wire that has been drawn to size and not annealed.
    HarnessAn arrangement of wires and cables, usually with many breakouts, which have been tied together or pulled into a rubber or plastic sheath, used to interconnect an electric circuit.
    Hash Mark StripeA non-continuous helical stripe applied to a conductor for identification.
    Heat DistortionDistortion of flow of a material or configuration due to the application of heat.
    Heat EnduranceThe time of heat aging that a material can withstand before failing a specific physical or electrical test.
    Heat ResistanceAbility of a substance to maintain physical and chemical identity and electrical integrity under specified temperature conditions.
    Heat SealIn cabling, a method of sealing a tape wrap jacket by means of thermal fusion.
    Heat ShockA test to determine stability of a material by sudden exposure to a high temperature for a short period of time.
    Heater CordFlexible stranded copper conductor, cotton wrapped with rubber insulation and asbestos roving .
    Helical StripeA continuous, colored, spiral stripe applied over the outer perimeter of an insulated conductor for circuit identification purposes.
    HelixSpiral winding.
    HenryUnit of inductance such that the induced voltage in volts is numerically equal to the rate of change in current in amperes per second.
    Hermetically SealedA gas-tight enclosure that has been completely sealed by fusion or comparable means.
    HertzUnit of measure of frequency of alternating current. One hertz is equal to one cycle per second.
    Hertz (Hz)A term replacing cycles-per-second as a unit of frequency.
    Heterogeneous InsulationA cable insulating system composed of two or more layers of different insulating materials.
    High Temperature Wire and CableElectrical wire and cables having thermal operating characteristics of 150°C and higher.
    High Voltage (HV)Cables rated over 35Kv. The National Electrical Code defines any cable over 600 volts as High Voltage for the purposes of Article 710. However, Article 326 delineates the generally accepted parameters of Medium Voltage and High Voltage .
    Hi-Pot (High Potential)A test designated to determine the highest voltage that can be applied to a conductor without breaking down the insulation (see Dielectric Test).
    Holding StrengthAbility of a connector to remain assembled to a cable when under tension.
    Homogeneous InsulationA complete cable insulation structure whose components cannot be identified as layers of different materials.
    Hook-up WireA single insulated conductor used for low current, low voltage (usually under 600 volts) applications within enclosed electronic equipment.
    Horizontal CablingThe wiring/cabling between the telecommunications outlet/connector and the horizontal cross-connect.
    Horizontal Cross-ConnectA cross-connect of horizontal cabling to other cabling, i.e. horizontal, backbone, or equipment.
    Horizontal StripeA colored stripe running horizontally with the axis of a conductor, sometimes called a longitudinal stripe, used as a means of circuit identification.
    Hybrid CableAn assembly of two or more cables (of the same or different types or categories) covered by one overall sheath.
    HygroscopicA material capable of absorbing and retaining moisture from the air.
    Hypalon®Dupont’s trade name for their chlorosulfonated polyethylene, an ozone resistant synthetic rubber.
    HzAbbreviation for Hertz.
    ICEAAbbreviation for Insulated Cable Engineers Association. (Formerly IPCEA).
    IECInternational Electrotechnical Commission, similar to the ISO in structure and scope.
    IEEEAbbreviation for Institute of Electrical and Electronics Engineers.
    Ignition CableCable designed for Automotive Ignition Systems.
    Impact StrengthA test for determining the mechanical punishment a cable can withstand without physical or electrical breakdown by impacting with a given weight, dropped a given distance, in a controlled environment.
    Impact ToolDevice used to punch new conductor onto ID’s. This tool is typically equipped with a cutting blade for either 66 or 110 blocks.
    ImpedanceThe total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency. It is a combination of resistance R and reactance X, measured in ohms.
    Impedance MatchA condition in which the impedance of a particular circuit cable or component is the same as the impedance of the circuit, cable or device to which it is connected.
    Impedance MatchingConnecting cables and devices together which have the sameimpedance value in ohms.
    Impedance Matching TransformerA transformer designed to match the impedance of one circuit to that of another (BALUN).
    ImpregnateTo fill the voids and interstices of cable or the fabric of a cable with a compound.
    Impulse (or Pulse)A surge of unidirection a polarity.
    Impulse StrengthThe voltage breakdown of insulation under voltage surges on the order of microseconds in duration.
    Impulse TestAn insulation test in which the voltage applied is an impulse voltage of specified wave shape.
    Incoherent SourceA light source which emits wide, diffuse beams of light of many wave lengths.
    Index Matching FluidFluid with refractive index same as fiber core; used to fill air gap between fiber ends at connectors.
    Index of RefractionThe ratio of light velocity in a vacuum to its velocity in a given transmission medium.
    Induced CurrentAn electric current set up in a circuit by cutting lines of force; a current caused by electromagnetic induction.
    InductanceThe property of a circuit or circuit element that opposes a change in current flow, causing current changes to lag behind voltage changes. It is measured in Henrys.
    InductionThe phenomenon of a voltage, magnetic field, or electrostatic charge being produced in an object by lines of force from the source of such fields.
    Inductive CouplingCrosstalk resulting from the action of the electromagnetic field of one conductor on the other.
    Infrared (IR)The range of electromagnetic wavelengths between the visible part of the spectrum (750 nm) and microwaves (30 µm).
    Infrastructure, TelecommunicationsA collection of those telecommunications components, excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.
    Insertion LossAs measure of the attenuation of a device by determining the output of a system before and after the device is inserted into the system .
    Insertion ToolA small, hand-held tool used to insert contacts into a connector.
    Inside Plant (ISP)All cable and equipment inside a central office or subscriber’s premises.
    Inside WireWire designed to carry a telephone circuit(s) through the customer’s premises.
    Insulated WireA conductor of electricity covered with a non-conducting material.
    Insulating JointA device which mechanically couples and electrically insulates the sheath and armor of contiguous lengths of cable.
    InsulationA material having good dielectric properties permitting close assembly of conductors in cable and equipment.
    Insulation AdhesionThe degree of tightness of the insulation over the base conductor, measured in terms of force required to remove a specified length of insulation from the wire.
    Insulation CrimpThe area of a terminal, splice, or contact that has been formed around the insulation of the wire .
    Insulation GripExtended cylinders at the rear of crimp-type contacts designed to accept the bared wire and a small length of its insulation.
    Insulation LevelA designation used to identify the insulation thickness required to protect a high voltage cable under ground fault conditions. Expressed as a percentage (e.g. 100% level, 133% level).
    Insulation PiercingA method of crimping whereby lances cut the insulation of the wires and enter into the strands to make electrical contact.
    Insulation ResistanceThat property of an insulating material which resists electrical current flow through the insulating material when a potential difference is applied.
    Insulation Shield (HV Cable)A two part shield consisting of a non-metallic component and a metallic component. The first component is an extrusion of black semi-conducting thermoset material over the insulation which provides uniform radial stress distribution across the insulation.
    Insulation StressHigh voltage stress which causes molecular separation in the insulation at sharp projections in the conductor. Controlled by conductor and insulation shielding, called a stress relief shield. Measured in volts per mil.
    Insulation SystemAll of the insulation materials used to insulate a particular electrical or electronic product.
    Insulation ThicknessThe wall thickness of the applied insulation.
    Integral BeltA layer of insulation or semi-conductive material applied by extrusion over two or more insulated, twisted or parallel conductors to form a round smooth diameter.
    Interaxial SpacingCenter to center conductor spacing.
    InterbuildingBetween buildings.
    InterconnectA connection scheme that provides for the direct connection of individual cables to another cable or to an equipment cable without a patch cord.
    Interconnecting CableThe wiring between modules, between units, or the larger portions of a system.
    Interconnecting WireThe physical wiring between components (outside a module) between modules, between units or between larger portions of a system or systems.
    InterconnectionMechanically joining devices together to complete an electrical circuit.
    InterfaceThe two surfaces on the contact side of both halves of a multiple-contact connector which face each other when the connector is assembled.
    InterferenceAny to electrical signal induced into a conductor by electrical or electro-magnetic means.
    Intermediate Cross-ConnectA cross-connect between 1st level and 2nd level backbone cabling.
    Internal WiringElectronic wiring which interconnects components, usually within a sealed subsystem.
    IntersticesVoids or valleys between individual strands in a conductor or between insulated conductors in a multiconductor cable.
    IntrabuildingWithin a building.
    IonizationGenerally the dissociation of an atom or molecule into positive or negative ions or electrons. Restrictively, the state of an insulator whereby it facilitates the passage of current due to the presence of charged particles usually induced artificially.
    Ionization Voltage (Corona Level)The minimum value of falling rms voltage which sustains electrical discharge within the vacuous or gas filled spaces in the cable construction or insulation.
    IrradiationIn insulations, the exposure of the material to high energy emissions for the purpose of favorably altering the molecular structure by crosslinking.
    ISDN (Integrated Service Digital Network)A digital data communications network providing full integration of data, voice and video.
    ISOInternational Standards Organization
    JackA plug-in type terminal widely used in electronic apparatus for temporary connections.
    JacketA material covering over a wire insulation or an assembly of components. An overall jacket on a complex cable grouping is also often referred to as a sheath. In fiber optics, a covering over a fiber, bundle of fibers, or cable which protects against th
    JouleA joule is a measurement of energy y. The joule rating on a surge protector indicates the amount of energy that a device is capable of absorbing. In general, the higher the joule rating, the better the unit is able to pro t e c t your equipment and the lo
    JumperAn assembly of twisted pairs without connectors used to join telecommunications circuits/links at the cross-connect. In fiber optic cable the cable that has connectors terminated on both ends.
    Jumper CableA short flat cable interconnecting two wiring boards or devices.
    Jumper WirePVC insulated connectors twisted together and used for cross-connecting on distributing frames.
    JunctionA point in a circuit where two or more wires are connected.
    JuteA natural fiber of plant base formed into rope-like strands. Used in cables for filling the interstices to give a round cross-section.
    kcmilOne thousand circular mils (MCM).
    KEMA KEURApproval agency of the Netherlands
    KevlarDuPont’s trade name for Aramid material (see Aramid Yarn).
    KeyingThe mechanical feature of a connector system that guarantees correct orientation of a connection, or prevents the connection to a jack, or to an optical fiber adapter of the same type intended for another purpose.
    KiloA numerical prefix denoting 1000.
    KilocycleA term denoting one thousand cycles. (See Kilohertz)
    KilohertzOne thousand hertz, or one thousand cycles per second.
    KilometerUnit of measure for length equal to 1000 meters and about 3,281 feet.
    KilovoltA term denoting one thousand volts.
    KilowattA term denoting one thousand watts.
    kVKilovolt (1000 volts).
    KynarPennwalt trade name for polyvinylidene fluoride. Typically used as insulation for wirewrap wire.
    Lacing and HarnessingA method of grouping wires by securing them in bundles of designated patterns.
    LacquerThe term used in cable manufacture to designate the liquid resin or compound applied to a fibrous braid to prevent fraying, wicking, moisture absorption, etc., in the braid.
    Laminated Flat CableFlat cable consisting of insulated conductors lying parallel, adjacent conductors joined by a web. Application in electronics, telecommunications, computers, etc.
    Laminated TapeA tape consisting of two or more layers of different materials bonded together (i.e. aluminum/Mylar®) .
    Lamp CordFlexible stranded paralleled 2-conductor cord, rubber or plastic insulated. Used for speaker cord, fans, lamps, etc., where not subject to hard usage.
    LAN (Local Area Network)A network spanning a limited geographical area, providing data communications between computers and peripherals and switching equipment.
    LaserA device which produces a narrow band of light and is used as a transmitting device for light signals traveling along optical fibers. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation.
    Laser DiodeA semiconductor diode that, when pulsed, a laser diode emits coherent light.
    Launch AngleAngle between the propagation direction of the incident light and the optical axis of an optical waveguide.
    LayThe length measured along the axis of a wire or cable required for a single strand (in stranded wire) or conductor (in cable) to make one complete turn about the axis of the conductor or cable.
    Lay DirectionThe twist in the cable as indicated by the top strands while looking along the axis of the cable away from the observer. Described as right hand or left hand.
    LayerConsecutive turns of a coil lying in a single plane.
    LeadA wire, with or without terminals, that connects two points in a circuit.
    Lead CuredA cable that is cured or vulcanized in a metallic lead mold.
    Lead DressThe placement or routing of wire and component leads in an electrical circuit.
    Lead-inThe conductor or conductors that connect the antenna proper to electronic equipment.
    Leakage CurrentThe undesirable flow of current through or over the surface of an insulation.
    LEDAcronym for Light Emitting Diode. It is a semiconductor device that emits incoherent light from a p-n junction (when biased with an electrical current).
    Life CycleA test performed on a material or configuration to determine the length of time before failure in a controlled, usually accelerated environment.
    LightIn the laser and optical communications fields, the portion of the electromagnetic spectrum that can be handled by the basic optical techniques used for the visible spectrum extending from the near ultraviolet region of approximately 0.3 micron, through t
    Light Commercial BuildingA building or portion thereof that is intended for use with one to four (1-4) non-residential exchange access lines per tenant.
    Light DiffusionScattering of light by reflection or transmission. Diffuse reflection results when light strikes an irregular surface such as a frosted window or coated light bulb.
    Light Emitting DiodeA semiconductor device that emits incoherent light from a p-n junction (when biased with an electrical current). Commonly called LED.
    Light Intensity RatioRatio of input light intensity to the output light intensity.
    Light SourceAn object capable of emitting light. In fiber optics, the light source is normally an LED or a laser.
    LightguideA flexible bundle of fibers used to transmit light.
    Light-Intensity RatioRatio of input light intensity to the output light intensity.
    Lightwave CommunicationsCommunications using light to carry the information.
    LightwavesElectromagnetic waves in the region of optical frequencies. The term “light” was originally restricted to radiation visible to the human eye, with wavelengths between 400 and 700 nm. However, it has become customary to refer to radiation in the speed regi
    Limiting Oxygen IndexPercentage of oxygen necessary to support combustion of a specified material.
    Limits of ErrorThe maximum deviation (in degrees or percent) of a thermocouple or thermocouple extension wire from standard emf temperature to be measured.
    LimpnessThe ability of a cable to lay flat or conform to a surface.
    Line BalanceThe degree to which the conductors of a cable are alike in their electrical characteristics with respect to each other, to other conductors, and to ground .
    Line CordA cord terminating in a plug at one end used to connect equipment or appliances to a power outlet.
    Line DropA voltage loss occurring between any two points in a transmission line due to there sonance reactance or leakage of the line.
    Line LossThe total of the various energy losses occurring in a transmission line.
    Line VoltageThe value of the potential existing on a supply or power line. Rated voltage of cables.
    LinkAn assembly of telecommunications facilities between two points, not including terminal equipment.
    ListedEquipment included in a list published by an organization, acceptable to the authority having jurisdiction, that maintains periodic inspection of production of listed equipment, and whose listing states either that the equipment or material meets appropri
    LOCAAbbreviation for loss of coolant accident, a system malfunction associated with nuclear generating stations.
    Local Area Network (LAN)A geographically limited communications network intended for the local transport of data, video, and voice.
    Longitudinal ShieldA tape shield, flat or corrugated, applied longitudinally with the axis of the core being shielded.
    Longitudinal WrapA tape applied longitudinally with the axis of the core being covered, as opposed to a helical, or spiral, tape wrapped core.
    Loop ResistanceThe total resistance of two conductors measured round trip from one end. Commonly used term in the thermocouple industry.
    Looping-inWiring method which avoids tee joints by carrying the conductor or cable to and from the point to be supplied.
    Loose-TubeType of cable design in which coated fibers are encased in buffer tubes offering excellent fiber protection and segregation. Mainly used in outdoor cable types.
    LossEnergy dissipated without accomplishing useful work.
    Loss FactorThe product of the dissipation and dielectric constant of an insulating material.
    Lossy LineA cable having large attenuation per unit of length.
    Low Loss DielectricAn insulating material that has a relatively low dielectric loss, such as polyethylene or Teflon.
    Low Noise CableCable configuration specially constructed to eliminate spurious electrical disturbances caused by capacitance changes or self-generated noise induced by either physical abuse or adjacent circuitry.
    Low TensionLow voltage, as applied to ignition cable.
    Low VoltageDefined by the National Electrical Code as 600 Volts and less. AEIC, ICEA, and UL generally define cables rated up to 2KV as Low Voltage.
    LugA termination, usually crimped or soldered to the conductor, with provision for screwing on to the terminal.
    mAbbreviation for meter.
    mA. MilliampereOne-thousandth of an ampere (10-3).
    MacrobendingMacroscopic axial deviations of a fiber from a straight line.
    Magnet WireInsulated wire intended for use in windings on motor, transformer, and other coils for electromagnetic devices.
    Magnetic FieldThe region within which a body or current experiences magnetic force.
    Magnetic FluxThe rate of flow of magnetic energy across or though a surface (real or imaginary) .
    Magnetic NoiseCaused by current frequency. An AC powerline creates a magnetic field around that cable. This magnetic field causes the magnetic noise in neighboring control or instrumentation circuits.
    Main Cross-ConnectA cross-connect for first level backbone cables, entrance cables and equipment cables.
    Marker TapeA tape laid parallel to the conductors under the sheath in a cable, imprinted with the manufacturer ‘s name and the specification to which the cable is made. Other information such as date of manufacture may also be included.
    Marker ThreadA colored thread laid parallel and adjacent to the strands of an insulated conductor which identifies the cable manufacturer. It may also denote a temperature rating or the specification to which the cable is made.
    MCMOne thousand circular mils (kcmil).
    MDPEAcronym for Medium Density Polyethylene. MDPE is a form of polyethylene commonly used as a jacketing material for outdoor fiber optic cables. (See PE.)
    Media, TelecommunicationsWire, cable, or conductors used for telecommunications.
    Medium Voltage2001 Volts to 35KV.
    Meg or MegaA numerical prefix denoting 1,000,000 (106) .
    MegaHertzOne million Hertz.
    MegaradA unit for measuring radiation dosage.
    MegohmOne million ohms.
    MemberA group of insulated wires to be cabled with other stranded groups into multiple-membered cable.
    MessengerThe linear supporting member, usually a high strength steel wire, used as the supporting element of a suspended aerial cable. The messenger may be an integral part of the cable, or on the exterior.
    MftA popular abbreviation for 1000 ft.
    MhoThe unit of conductivity. The reciprocal of an Ohm.
    MHzMegahertz (one million cycles per second). Formerly mc.
    MicroA numerical prefix denoting one millionth.
    MicrobendingCurvatures of the fiber which involve axial displacements a few micrometers and spatial wavelengths of a few millimeters. Microbends cause loss of light and consequently increase the attenuation of the fiber.
    Microbending LossLoss due to small geometrical irregularities along the core-clad interface of the fiber.
    MicrofaradOne-millionth of a farad, commonly abbreviated mF.
    Micrometer (µm)One millionth of a meter or a micron. Conventional unit of measurement for optical fibers.
    MicromicrofaradOne-millionth of a microfarad (uuf, uufd, mmf, mmfd mm F are common abbreviations).
    Micron(m) Millionth of a meter = 10-6 meter.
    MicrophonicsNoise in a system caused by mechanical vibration of components within the system.
    MicrowaveA short (usually less than 30 cm) electrical wave.
    MilA unit used in measuring diameter of a wire or thickness of insulation over a conductor. One one-thousandth of an inch (0.001″).
    MilliA prefix denoting one-thousandth (10-3).
    Mineral InsulatedCable and thermocouple wire consisting of one or more conductors surrounded by magnesium oxide insulation and enclosed in a liquid- and gas-tight metallic sheathing.
    Miniature WireInsulated conductors of approximately 20-34 AWG.
    Mining CableA flame retardant cable especially constructed to withstand long time immersion or exposure to moisture for underground use in the environment of a mine or tunnel.
    MismatchA termination having a different impedance from that for which a circuit or cable is designed.
    Modal DispersionPulse spreading due to multiple light rays traveling different distances and speeds through an optical fiber.
    ModeOne of the components of a general configuration of a propagating wave front.
    Mode Field Diameter (MFD)The diameter of optical energy in a singlemode fiber. Because the MFD is greater than the core diameter, MFD replaces core diameter as a practical parameter.
    ModemDevice which places and receives data signals over a common carrier’s communication facility.
    Modular JackThis term is outmoded, see Outlet/Connector, Telecommunications.
    Modular PlugA telecommunications connector for wire or cords per the Part 68 Rules. A modular plug can have 6 or 8 contact positions but not all the positions need be equipped with contacts.
    ModulationA process whereby certain characteristics of a wave, often called the carrier, are varied or selected in accordance with a modulating function.
    Modulus of ElasticityThe ratio of stress to strain in an elastic material.
    Moisture AbsorptionThe amount of moisture , in percentage, that a material will absorb under specified conditions.
    Moisture AbsorptionThe amount of moisture, in percentage, that a material will absorb under specified conditions.
    Moisture ResistanceThe ability of a material to resist absorbing moisture from the air or when immersed in water.
    Molded PlugA connector molded on either end of a cord or cable.
    MonochromaticConsisting of a single wavelength. In practice, radiation is never perfectly monochromatic but, at best, displays a narrow band of wavelengths.
    MonomerThe basic chemical unit used in building a polymer.
    Multi-ConductorMore than one conductor within a single cable complex.
    Multi-Conductor CableA cable consisting of two or more conductors, either cabled or laid in a flat parallel construction, with or without a common overall covering.
    Multimedia CableA single communication cable used for the transmission of audio, data and video signals.
    Multimode FiberAn optical waveguide in which light travels in several modes. Typical core and cladding sizes are 62.5 and 125 µm, respectively.
    Multimode Optical FiberAn optical fiber that will allow many bound modes to propagate. The fiber may be either a graded-index or step-index fiber. See also: Optical Fiber Cable.
    Multiple Conductor Concentric CableAn insulated central conductor with one or more tubular stranded conductors laid over it concentrically and insulated from one another.
    Multiple-Conductor CableA combination of two or more conductors cabled together and insulated from one another and from sheath or armor where used.
    MultiplexCombining two or more signals into a single bit stream that can be individually recovered.
    MultiplexingSimultaneous transmission of two or more messages over the same cable pair.
    Mutual Capacitance (Cm)The capacitance between two conductors when all other conductors, including the shield, are short circuited to ground.
    Mutual InductanceThe ratio of voltage induced in one conductor to the time rate of current change in the separate conductor causing this induction.
    MylarDuPont’s trademark for polyethylene terephthalate (polyester) film used in the form of a tape.
    NanoA numerical prefix denoting one-billionth (10-9).
    Nanometer (nm)One billionth of a meter (10 -9 meter).
    NanosecondOne billionth of a second (10 -9 seconds).
    National Electrical Code® (NEC)A U.S. consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations. (The Canadian Counterpart is the CE Code.)
    NEMAAbbreviation for National Electrical Manufacturers Association. (The Canadian counterpart is EEMAC).
    NEMKOApproval agency of Norway.
    NeopreneA synthetic rubber with good resistance to oil, chemicals and flame. Also called polychloroprene.
    Network1) Series of points connected by communications channels; 2) Network of telephone lines normally used for dialed telephone calls; 3) Network of communications channels connected to the use of one customer. For purposes of data communications applications
    NEXTNear end cross talk
    NFPANational Fire Protection Association.
    NoiseIn a cable or circuit, any extraneous signal which tends to interfere with the signal normally present in or passing through the system.
    Nomex®DuPont’s trademark for a temperature resistant, flame-retardant nylon.
    Non HygroscopicA material incapable of taking up or absorbing moisture from the air.
    Non-ContaminatingType of PVC jacket material whose plasticizer will not migrate into the dielectric of a coaxial cable and thus avoids contaminating and destroying the dielectric.
    Numerical Aperture (NA)Measure of the range of angles of incident light transmitted through a fiber. Depends on the differences in index of refraction between the core and the cladding. (The number that expresses the light gathering ability of a fiber.)
    NVPNominal Velocity of Propagation.
    NylonAn abrasion resistant thermoplastic with good chemical resistance used for wire and cable jacketings.
    Off CenterConductor displaced within the cross-section of its insulation.
    OffgassingPercentage of a specified gas released during the combustion of insulation or jacketing material.
    OFHCAbbreviation for oxygen-free, high conductivity copper. It has no residual deoxidant, 99.95% minimum copper content and an average annealed conductivity of 101%.
    OhmA unit of electrical resistance, the resistance of a circuit in which a potential difference of one volt produces a current of one ampere.
    Oil AgingCable aged in an accelerated manner by placement in an oil bath and heated to a p re-set temperature for a stated time.
    Oil-Filled CableA self-contained pressure cable in which the pressure medium is low viscosity oil having access to the insulation.
    OpaqueNot permitting the passage of light.
    Open CellFoamed or cellular material with cells which are generally interconnected.
    Optical Communication CableFiber with a protective jacket.
    Optical ConductorsMaterials which offer a low optical attenuation to transmission of light energy.
    Optical Fiber CableAn assembly consisting of one or more optical fibers.
    Optical Fiber Duplex AdapterA mechanical media termination device designed to align and join two duplex connectors.
    Optical Fiber Duplex ConnectorA mechanical media termination device designed to transfer optical power between two pairs of optical fibers.
    Optical Return Loss (ORL)The ratio, expressed in decibels, of optical power reflected by a component or an assembly to the optical power incident on a component or assembly that is induced into a link or system.
    Optical Time Domain Reflectometer (OTDR)An instrument used to measure the transmission performance of optical fibers.
    Optical WaveguideDielectric waveguide with a core consisting of optically transparent material of low attenuation (usually silica glass) and with cladding consisting of optically transparent material of lower refractive index than that of the core. It is used for the tra
    Oscillatory SurgeA surge which includes both positive and negative polarity values.
    OSHAAbbreviation for Occupational Safety and Health Act. Specifically the Williams-Steiger law passed in 1970 covering all factors relating to safety in places of employment.
    OutgassingThe dissipation of gas from a dielectric evidencing decomposition.
    Outlet Box, TelecommunicationsA metallic or nonmetallic box mounted within a wall, floor or ceiling and used to hold telecommunications outlet/connectors or transition devices.
    Outlet/Connector, TelecommunicationsA connecting device in the work area on which horizontal cable terminates.
    Outside Plant (OSP)All cables and wires extending outward from the network protectors on the main distribution frame to connect the terminal equipment to the Outside Plant.
    OVEApproval agency of West Germany; Oesterreichischer Verband fur Elektrotechnik.
    Over CurrentThe current which causes an excessive temperature rise in a conductor.
    Overall DiameterFinished diameter over wire or cable.
    OvercoatIndividual strands of tinned copper wire stranded together and then covered with a tin coating.
    Overcoat ConductorA stranded conductor made from individual strands of tin coated wire stranded together, and then given an overall tin coat.
    OverlapThe amount the trailing edge laps over the leading edge of a spiral tape wrap.
    Overload CapacityThe maximum level of current, voltage, or power which a device can withstand before it is damaged.
    Oxygen IndexPercentage of oxygen necessary to support combustion in a gas mixture. Flame retardant materials have a higher oxygen index.
    OzoneReactive form of oxygen, typically found a round electrical discharges and present in the atmosphere in small quantities.
    Ozone TestExposure of material to a high concentration of ozone to give an accelerated indication of oxidation in normal environments and in proximity to ozone producing apparatus.
    Packing FractionThe ratio of active cross-sectional area of fiber core, or cores, to the total end surface of the fiber or fiber bundle.
    PairTwo wires forming a single circuit, held together by twisting, binding or a common jacket. Also known as a balance transmission line.
    PairingThe union of two insulated single conductors through twisting.
    PAPA commonly used term for air core (unfilled) direct burial telephone cable with a corrugated aluminum shield.
    ParallelA construction in which two or more conductors are laid parallel and surrounded and separated by an insulating material.
    Parallel CableTwo or more cables used to share the current in heavily loaded power circuits which permits the use of smaller conductors.
    Parallel PairA duplex construction of two insulated conductors laid parallel and then covered overall with a braid or jacket.
    Parallel StripeA stripe applied longitudinally on a wire or cable parallel to the axis of the conductor.
    PASPA cable sheath consisting of an inner polyethylene (P) jacket, corrugated aluminum (A) shield, corrugated steel (S) and an outer polyethylene (P) jacket.
    Patch CableA cable with plugs or terminals on each end of the conductors to temporarily connect circuits of equipment together.
    Patch CordA length of cable with connectors on one or both ends used to join telecommunications links/circuits at the cross-connect .
    Patch Cord CableBulk cable used in the manufacture of patch cords.
    Patch PanelA cross-connect system of mateable connectors that facilitates administration.
    PathwayA facility for the placement of telecommunications cable. Synonym: Raceway.
    Pay-OffThe process of feeding a cable or wire from a bobbin, reel, or other package.
    PBTPoly-Butylene Terephthalate. A type of plastic.
    PCBPrinted Circuit Board .
    PEAbbreviation used for polyethylene. Polyethylene is a type of plastic, commonly used as a jacketing material for outside plant cables,
    that possesses good mechanical properties including good moisture resistance. However, it is very flammable and not sui
    Peak VoltageThe maximum instantaneous voltage
    Percent ConductivityConductivity of a material expressed as a percentage of that of copper.
    Percentage ConductivityConductivity of a material expressed as a percentage of that of copper. Also used to indicate ratio of conductance between the phase conductor and the neutral in power cables.
    PeriodicityThe uniformly spaced variations in the insulation diameter of a transmission cable that result in reflections of a signal, when its wavelength or a multiple thereof is equal to the distance between two diameter variations.
    PermittivityThe ratio of the capacitance of a condenser with dielectric between the electrodes to the capacitance when air is between the electrodes. Also called Permittivity and Specific Inductive Capacity (SIC).
    PhaseA particular stage or point of advancement in an electrical cycle. The fractional part of the period through which the time has advanced measured from some arbitrary point usually expressed in electrical degrees where 360° represents one cycle.
    Phase ShiftA change in the phase relationship between two alternating quantities.
    Photodetector (Receiver)Converts light energy to electrical energy.
    PICAn abbreviation for Plastic Insulated Conductor: conductors covered with an extruded coating of plastic.
    PickDistance between two adjacent crossover points of braid filaments. The measurement in picks per inch indicates the degree of coverage.
    PICOA prefix denoting one-millionth of one-millionth (10-12).
    PicofaradOne trillionth of a farad. A unit capacitance usually used to designate capacitance unbalance between pairs and capacitance unbalance of the two wires of a pair to ground. (abbreviation pf)
    PigtailA fiber optic connector that is terminated to one end of an optical fiber cable. A short length of optical fiber, permanently fixed to a component, used to couple power between the component and a transmission fiber.
    Pigtail WireFine stranded, extra flexible, rope lay lead wire attached to a shield for terminating purposes.
    PitchIn flat cable, the nominal distance between the index edges of two adjacent conductors.
    Pitch DiameterDiameter of a circle passing though the center of the conductors in any layer of a multi-conductor cable.
    Plain ConductorA conductor consisting of only one metal.
    Planetary CablerA cabler capable of laying down any number of shielded, overbraided, jacketed single conductors or pairs, called groups, or any combination of them in sequence.
    Planetary TwisterA twisting machine whose payoff spools are mounted in rotating cradles that hold the axis of the spool in a fixed direction as the spools are revolved about one another so the wire will not kink as it is twisted.
    PlasticAlso called thermoplastic, high polymeric substances, including both natural and synthetic products, but excluding the rubbers, that are capable of flowing under heat and pressure.
    Plastic DeformationChange in dimensions under load that is not recovered when the load is removed.
    PlasticizerA chemical agent added in compounding plastics to make them softer and more flexible.
    PlatingThe application of one metal over another.
    PlenumThe air handling space such as that found above drop-ceiling tiles or in raised floors. It is also the most stringent fire code rating for indoor cables.
    Plenum CableA cable that meets the most stringent flammability and smoke-generating tests and is approved by a recognized agency such as UL for installation in plenums without the need for conduit.
    PlugThe part of the two mating halves of a connector which is movable when not fastened to the other mating half.
    PlyThe number of individual strands or filaments twisted together to form a single thread.
    Point-to-Point WiringAn interconnecting technique wherein the connections between components are made by wires routed between connecting points.
    PolarizationThe orientation of a flat cable or a rectangular connector.
    PolishingAct of smoothing ends of fibers to an optically smooth finish, generally using abrasive.
    PolychloropreneChemical name for Neoprene. A rubber-like compound used for jacketing where wire and cable will be subject to rough usage, moisture, oil, greases, solvents and chemicals. May also be used as low insulating material.
    PolyesterPolyethylene terephthalate which is used extensively in the production of a high strength moisture resistant film used as a cable core wrap (see Mylar).
    Polyethylene (PE)A family of insulating materials derived from polymerization of ethylene gas. They are basically pure hydrocarbon resins with excellent dielectric properties.
    HalogenatedA general name for polymers containing halogen atoms. The halogens are fluorine, chlorine, bromine and iodine.
    PolymerA substance made of many repeating chemical units or molecules. The term polymer is often used in place of plastic, rubber or elastomer.
    PolymerizationA chemical reaction in which low molecular weight molecules unite with each other to form molecules with higher molecular weights.
    PolyolefinA family of thermoplastics based upon the unsaturated hydrocarbons known as olefins. When combined with butylene or styrene polymers they form compounds such as polyethylene and polypropylene.
    Polypropylene (PPE)A thermoplastic similar to polyethylene but stiffer and having higher softening point (temperature); excellent electrical properties .
    Polyurethane (PUR)This thermoplastic material is used primarily as a cable jacket material. It has excellent oxidation, oil, and ozone resistance.
    Some formulations also have good flame resistance. It is a hard material with excellent abrasion resistance. It has outstandi
    Polyvinylchloride (PVC)A thermoplastic material composed of polymers of vinyl-chloride which may be rigid or elastomeric, depending on specific formulation.
    PorosityMultiple air voids in an insulation or jacket wall.
    Portable Power CableFlexible, all rubber insulated for hard usage. Some cables have shielded conductors (metallic or non-metallic) and can have neoprene sheath overall.
    PottingThe sealing of a cable termination or other component with a liquid which thermo-sets into an elastomer or solid compound to exclude moisture .
    PowerThe rate at which energy is transferred.
    Power CablesCables of various sizes, construction and insulation, single or multi-conductor, designed to distribute primary power to various types of equipment .
    Power FactorThe ratio of resistance to impedance. The ratio of the actual power of an alternating current to apparent power. Mathematically, the cosine of the angle between the voltage applied and the current resulting.
    Pre-BondStranded wire which has been fused, topcoat tinned, or overcoat tinned.
    PreformA glass structure from which an optical fiber waveguide can be drawn.
    PressurizationThe use of pressurized gas or dry air inside Air Core cables to prevent the entry of water at faulty splices or minor sheath cracks. It can also trigger an alarm when major faults occur and can assist in locating the damaged areas.
    Pre-WiringThe practice of concealing station wire or cable in the walls of buildings while they are being constructed. It is cheaper and more satisfactory for the owner.
    PrimaryThe transformer winding which receives the energy from a supply circuit.
    Primary CoatingThe plastic coating applied directly to the cladding surface of the fiber during manufacture to preserve the integrity of the surface.
    Primary InsulationA non-conductive material, usually the first layer over a current carrying conductor, whose prime function is to act as an electrical barrier for the applied potential.
    Primary ProtectionThe minimum protection required on all exposed facilities to comply with NEC requirements.
    Primary WiringA printed circuit intended to provide point-to-point electrical connections.
    ProgrammingAbility to select various circuit patterns by interconnecting appropriate contacts on one side of a connector plug or panel.
    Propagation DelayTime required for a signal to pass from the input to the output of a device.
    Propagation TimeTime required for an electrical wave to travel between two points on a transmission line.
    ProtocolA set of rules for communicating.
    Proximity EffectNon-Uniform current distribution over the cross-section of a conductor caused by the variation of the current in a neighboring conductor.
    PTFEAbbreviation for Polytetrafluoroethylene.
    Pull BoxA device to access a raceway used to facilitate placing of wire or cables.
    Pull Cord/Pull WireCord or wire placed within a raceway and used to pull wire and cable through the raceway.
    Pull StrengthThe maximum pulling force that can be safely applied to a cable without damage.
    Pull TensionThe maximum pulling force that can be safely applied to a cable without damage.
    Pulling EyeA device which may be fastened to the conductor or conductors of a cable or formed by or fastened to the wire armor and to which a hook or rope may be directly attached in order to pull the cable into or from a duct.
    PulseA current or voltage which changes abruptly from one value to another and back to the original value in a finite length of time. Used to describe one particular variation in a series of wave months.
    Pulse CableA type of coaxial cable constructed to transmit repeated high voltage pulses without degradation.
    Put-UpRefers to the packaging of wire and cable. The term itself refers to the quantity of product that is ready to be stored or shipped.
    PVCAbbreviation used for polyvinyl chloride. Polyvinyl chloride is a plastic material that is widely used as a jacketing material in indoor cables.
    PVDFAbbreviation denoting polyvinylidene fluoride, a fluoropolymer plastic material often used as a jacket in plenum cables, especially in larger fiber count cables.
    QuadA series of four separately insulated conductors, generally twisted together in pairs. Also, a series-parallel combination of transistors with increased reliability because failure of one transistor will not disable the entire circuit.
    QuaddersThree-bay machines which can twist four wires together and cable braided and shielded wires with varying lay lengths.
    RacewayAny channel designed for holding wires or cables, i.e. conduit, electrical metallic tubing, sleeves, slots, underfloor raceways, cellular floors, surface raceways, lighting fixture raceways, wireways, cable troughs, busways, auxiliary gutters, and ventila
    RackThe vertical or horizontal open support (usually made of aluminum or steel) that is attached to a ceiling or wall.
    Radio FrequencyThe frequencies in the electromagnetic spectrum that are used for radio communications.
    Random WindingA winding in rotating equipment wherein the wires do not lie in an even pattern .
    Rated TemperatureThe maximum temperature at which an electric component can operate for extended periods without loss of its basic properties.
    Rated VoltageThe maximum voltage at which an electric component can operate for extended periods without undue degradation or safety hazard .
    ReactanceThe opposition offered to the flow of alternating current by the inductance or capacitance of a component or circuit.
    Reactance DropWith AC, that component of the voltage drop which is in quadrature with the current and equals the current in amperes multiplied by the reactance in ohms between the two points.
    ReceiverA detector and electronic circuitry to change optical signals into electrical signals.
    Red PlaqueA powdery, brown-red growth found on silvercoated copper conductors and shield braids.
    RedrawThe drawing of wire which has already been drawn to an intermediate size, through a series of dies, to reach a desired wire size.
    Reducing JointA joint between two lengths of cable where the conductors are not the same size.
    ReelA revolvable flanged device made of wood or metal, used for winding flexible metal wire or cable.
    Reel Drum DiameterDiameter of the drum (or hub) of the reel.
    Reel Flange Diameter (Reel Height)Diameter of the reel flanges
    Reel TraverseWidth of space between reel flanges.
    Reel WidthOverall width of reel.
    Reference JunctionThe junction of a thermocouple which is at a known reference temperature. Also known as the cold junction. It is usually located at the emf measuring device.
    ReflectionThe abrupt change in direction of a light beam at an interface between two dissimilar media so that the light beam returns into the media from which it originated.
    Reflection LossThe part of a signal which is lost due to reflection of power at a line discontinuity.
    Reflow SolderingThe process of connecting two solder-coated conductive surfaces by remelting of the solder to cause fusion.
    RefractionThe bending of a beam of light at an interface between two dissimilar media or in a medium whose refractive index is a continuous function of position (graded index medium).
    Refractive IndexThe ratio of the velocity of light in a vacuum to that in an optically dense medium.
    RegistrationAlignment of one object with relation to another. Also called Register.
    Reinforced SheathThe outermost covering of a cable that has a cable sheath construction in layers with a reinforcing material, usually a braided or double spiral fiber, molded in place between layers.
    ReinforcementA material used to reinforce strengthen or give dimensional stability to another material.
    RemanenceThe magnetic induction that remains in a magnetic circuit after the removal of an applied magnetomotive force.
    RepeaterA device which consists of a transmitter and a receiver or transmitter, used to regenerate a signal to increase the system transmission length. In an optical-fiber communication system, an optoelectronic device or module that receives an optical signal,
    ResinAn organic substance of natural or synthetic origin characterized by being polymeric in structure and predominantly amorphous. Most resins, though not all, are of high molecular weight and consist of long chain or network molecular structure.
    ResistanceA measure of the difficulty in moving electrical current through a medium when voltage is applied. It is measured in o h m s .
    Resistive ConductorA conductor with high electric resistance.
    Retractile CableA cable that returns by its own stored energy from an extended condition to its original contracted form.
    Retractile CordA cord having specially treated insulation or jacket so that it will retract.
    Return LossBackward reflected energies from uneven parts of the cable structure causing impedance variations. Return Loss is necessary for bi-directional applications.
    Return WireA ground wire or the negative wire in a direct-current circuit.
    RFAbbreviation for radio-frequency.
    RFIRadio Frequency Interference.
    RG/URadio Government, Universal. RG is the military designation for coaxial cable and U stands for general utility.
    Ridge MarkerOne or more ridges running laterally along the outer surface of a plastic insulated wire for purposes of identification.
    Rigid BayCabling equipment that maintains component sequence, and can produce cables with distinct layers.
    Rigid Coaxial CableNon-flexible coaxial cable, usually a metal tube armored coaxial cable.
    Ring BandingA circumferential color band applied to an insulated conductor at regular intervals for identification.
    Ring TongueA solderless terminal that connects wire to a stud.
    Ringing OutThe process of locating or identifying specific conductive paths by means of passing current through selected conductors.
    Rip Cord(1) Two or more insulated conductors in a parallel configuration which may be separated to leave the insulation of each conductor intact; (2) A small filament cord used to rip through the outer cable sheath.
    RiserPathways for indoor cables that pass between floors. It is normally a vertical shaft or space. A riser cable rating indicates good flammability characteristics, but not necessarily low smoke as in a plenum type.
    Riser CableThe vertical section of a building cable extending from one floor to another.
    Root Mean Square (RMS)The effective value of an alternating current or voltage.
    Rope ConcentricA group of standard conductors assembled in a concentric manner.
    Rope Lay ConductorA conductor composed of a central core surrounded by one or more layers of helically laid groups of wires used in portable cables.
    Rope StrandA conductor composed of a center group of twisted strands surrounded by one or more layers of similar groups of twisted strands.
    Rope UnilayA group of stranded conductors assembled in a unilay manner.
    Round ConductorA conductor whose cross-section is substantially circular.
    Round Wire ShieldsShields constructed from bare, tinned or silver plated copper wire that include braided, spiral, and reverse spiral.
    RoutersA device that determines how to forward a packet toward its destination, based on tables that indicate the costs, congestion status, and other factors associated with possible routes. Also called a Level 3 Relay or an Intermediate System.
    RoutingThe path followed by a cable or a conductor.
    RubberA general term used to describe wire insulation and jackets made of thermosetting elastomers, such as natural or synthetic rubbers, EPR, neoprene, Hypalon, butyl rubber and others.
    RuptureIn the breaking strength or tensile strength tests, the point at which the material physically comes apart, as opposed to elongation, yield strength, etc.
    SHeavy duty, rubber-insulated portable cord . Stranded copper conductors with separator and individual rubber insulation. Two or more color coded conductors cabled with filler wrapped with separator and rubber jacketed overall. 600V.
    SBCSoft bare copper.
    SBRA copolymer of styrene and butadiene. Also GR-S or Buna-S. Most commonly used type of synthetic rubber.
    ScatteringProperty of glass that causes light to deflect from the fiber and contributes to optical attenuation.
    ScreenA shield placed over the entire core.
    Screened CablesA cable core design where an aluminum shield divides the cable core into two electrically separate compartments.
    Secondary InsulationA nonconductive material that protects the conductor against abrasion and provides a second electrical barrier.
    Segmental ConductorA stranded conductor consisting of three or more stranded conducting elements, each element having approximately the shape of the sector of circle, assembled to give a substantially circular cross-section.
    Self ExtinguishingThe characteristic of a material whose flame is extinguished after the igniting flame is removed.
    Self-Supporting Aerial CableA cable consisting of one or more insulated conductors factory-assembled with a messenger which supports the assemblage and which may or may not form a part of the electrical circuit.
    Self-Supporting CableAny assemblage of conductors which incorporates a steel rope or steel sheath for added tensile strength, thus enabling it to be suspended between widely spaced supports.
    Semi-Conducting JacketA jacket having a sufficiently low resistance so that its outer surface can be kept at substantially ground potential.
    Semi-Conducting TapeA tape of such resistance that when applied between two elements of a cable, the adjacent surfaces of the two elements will maintain substantially the same potential.
    Semi-ConductorIn wire industry terminology, a material possessing electrical conductivity that falls somewhere between that of conductors and insulators. Usually made by adding carbon particles to an insulator (e.g. conductor shield and insulation shield). Not the same
    Semi-RigidA cable containing a flexible inner-core and a relatively inflexible sheathing material, such as a metallic tube, but which can be bent for coiling or spooling and placing in a duct or cable run.
    Semi-Rigid PVCA hard semi-flexible polyvinylchloride compound with low plasticizer content.
    Semi-SolidAn insulation cross-section having a partially open space between the conductor and the insulation perimeter.
    SEMKOApproval agency for Sweden.
    SeparatorA layer of insulating material which is placed between a conductor and its dielectric, between a cable jacket and the components it covers, or between various components of a multiple-conductor cable.
    Series CircuitA circuit in which the components are arranged end-to-end to form a single path for current.
    ServeA filament or group of filaments such as fibers or wires, wound around a central core
    Served Wire Armor (SWA)Spiral wrap of soft galvanized steel wires applied to a cable to afford mechanical protection and increase the cable pulling tension characteristics.
    ServingA wrapping applied over the core of a cable or over a wire.
    SheathThe combination of a metallic shield and an extruded plastic jacket applied as the outermost covering on a cable. In the absence of a shield, the extruded jacket may be designated as a sheath.
    ShieldA metallic layer placed around an insulated conductor or group of conductors to prevent electrostatic or electro magnetic interference between the enclosed wires and external fields. This shield can be braided or served wires, foil wrap, foil backed tape
    Shield (Electrostatic)In cables, a metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields. Also see Insulation Shield.
    Shield CoverageThe physical area of a cable that is actually covered by the shielding material and is expressed in percentage.
    Shield EffectivenessThe ability of a shield to screen out undesirable signals.
    Shielded LineA transmission line whose elements confine propagated radio waves to an essentially finite space inside a tabular conducting surface called the sheath preventing the line from radiating radio waves .
    Shielded-Type CableA cable in which the surface of the insulation is at ground potential.
    Shock TestA test to determine the ability of a cable to withstand a violent physical concussion such as might occur during handling or use.
    Shrink TubingTubing which has been extruded, crosslinked, and mechanically expanded which when reheated will return to its original diameter.
    Shunt WireA conductor joining two parts of an electric circuit to divert part of the current.
    SIASteel Interlocked Armor.
    SICSpecific Inductive Capacity.
    Side Wall Bearing Pressure (SWBP)A term used in reference to the pressure on a cable which is being pulled around a curved surface under tension. If excessive, SWBP can damage cable components and reduce the life of the cable.
    SignalA current used to convey information, either digital, analog, audio or video.
    Signal CableA cable designed to carry current of usually less than one ampere per conductor to operate signal circuit devices.
    SiliconeA material made from silicone and oxygen. It can be in thermosetting elastomer or liquid form. The thermosetting elastomer form is noted for high heat resistance.
    Silicone TreatingA silicone liquid treatment applied to insulated conductors to allow for easy jacket stripping.
    SimplexTransmission in only one direction. Generally a communications system or device capable of transmission in one direction only.
    Sine WaveA wave that can be expressed as the sine of a linear function of time, or space or both.
    Single Mode FiberA fiber wave guide in which only one mode will propagate. The fiber has a very small core diameter of approximately 8mm. It permits signal transmission at extremely high bandwidths and is generally used with laser diodes.
    Single-EndedUnbalanced, such as grounding one side of a circuit or transmission line.
    Single-Faced TapeFabric tape finished on one side with a rubber or synthetic compound.
    Singlemode FiberOptical fiber with a small core diameter (typically 9 µm) in which only a singlemode, the fundamental mode, is capable of propagation. This type of fiber is particularly suitable for wideband transmission over large distances, since its bandwidth is limit
    SizingApplying a material to a surface to fill pores.
    Skew RaysA ray that does not intersect the fiber axis. Generally, a light ray that enters the fiber core at a very high angle.
    Skim TapeFilled tape coated on one or both sides with a thin film of uncured rubber or synthetic compound to produce a coating suitable for vulcanization.
    Skin EffectThe tendency of alternating current to concentrate and to travel only on the surface of a conductor. Tendency increases with increase in frequency.
    SleeveA braided, knifed, or woven tube used over wires or components as insulation tubing. Also called Sleeving.
    SleevingAn extruded tube.
    SolderA metal or metallic alloy used when melted to join metallic surfaces. To unite or join by solder.
    Solid ConductorA conductor consisting of a single wire.
    SourceA light emitter, either an LED or laser diode, in a fiber optic link; a device that when properly driven will produce information carrying optical signals.
    Source Coupling LossLoss of light intensity as light from source passes into fiber.
    Space, TelecommunicationsAn area used for housing the installation and termination of telecommunications equipment and cable, i.e., telecommunications closets, work areas and manhole/handholes.
    SpacingDistance between the closest edges of two adjacent conductors.
    Span(1) In flat conductors, the distance between the reference edge of the first and the last conductor; (2) In round conductors, the distance between centers of the first and last conductors ; (3) In aerial cable, the distance between poles or support clamp
    Spark TestA test designed to locate imperfections (usually pin-holes) in the insulation of a wire or cable by application of voltage for a very short period of time while the wire is being drawn through the electrode field.
    Specific GravityThe ratio of the weight of any volume of substance to a weight of an equal volume of some substance taken as a standard, usually water for liquids and hydrogen for gases.
    Specific Inductive Capacity (SIC)Same as dielectric constant (See Dielectric Constant).
    Spectral BandwidthThe difference between wavelengths at which the radiant intensity of illumination is half its peak intensity.
    Spectral ResponseThe response of a detector (or a system) over different wavelengths.
    SpectrumFrequencies that exist in a continuous range and have a common characteristic.
    Speed of Light186,000 miles per second.
    Spiral MarkingA continuous spiral mark applied to a conductor for identification.
    Spiral ShieldA metallic shield of fine stranded wires applied spirally rather than braided.
    Spiral StripeA color coding stripe applied helically to the surface of an insulated wire or cable.
    Spiral WrapThe helical wrap of a tape or thread over a core.
    SpliceA connection of two or more conductors or cables to provide good mechanical strength as well as good conductivity.
    Splice ClosureA device used to protect a cable or wire splice.
    SpoolA revolvable flanged device made of wood or metal, used for winding flexible metal wire or cable.
    Spread SpectrumA modulation technique for multiple access, or for increasing immunity to noise and interference.
    Square MilThe area of a square one mil by one mil.
    Stability FactorThe difference between the percentage power factor at 80 volts/mil and at 40 volts/mil measured on wire immersed in water at 750C for a specified time.
    Standing WaveThe stationary pattern of waves produced by two waves of the same transmission line. The existence of voltage and current maxima and minima along a transmission line is a result of reflected energy from an impedance mismatch.
    Standing Wave Ratio (SWR)In a transmission line, waveguide, or analogous system, a figure of merit used to express the efficiency of the system in transmitting power.
    Star TopologyA topology in which each telecommunications outlet/connector is directly cabled to the distribution device.
    Static ConditionUsed to denote the environmental conditions of an installed cable rather than the conditions existing during cable installation.
    Station WirePVC jacketed wire specially designed for use in ducts or stapled to surfaces for direct connection to subscriber’s phone.
    Stay CordA component of a cable used to anchor the cable ends at their points of termination and to keep any pull of the cable f rom being transferred to the electrical connections.
    Step Index FiberA fiber having a uniform refractive index within the core and a sharp decrease in refractive index at the core/cladding interface.
    Strand(1) A single uninsulated wire; (2) One of the wires of any stranded conductor.
    Strand Conductor ShieldA layer of semiconducting material or tape applied directly over the stranded conductor of cables rated 2,000 volts and higher. This reduces the possibility of high stress points occurring between the conductor and insulation.
    Strand LayA distance of advance of one strand of a spirally stranded conductor, in one turn, measured axially.
    Stranded ConductorA conductor composed of individual groups of wires twisted together to form an entire unit.
    StrapSquare- or rectangular-section bare conductor manufactured and used in coil form.
    Strength MemberPart of a fiber optic cable composed of aramid yarn, steel strands, or fiberglass filaments that increase the tensile strength of the cable.
    StripTo remove insulation from a cable.
    Strip ForceThe force required to remove a small section of insulating material from the conductor it covers.
    Structural Return LossBackward reflected energies from uneven parts of the cable structure causing impedance variations are termed structural return loss.
    Suggested Working VoltageAC voltage that can be applied between adjacent conductors.
    Surface ResistivityThe resistance of a material between two opposite sides of a unit square of its surface. It is usually expressed in ohms. A temporary and relatively large increase in the voltage or cur rent in an electric circuit or cable. Also called Transient.
    SurgeA temporary and relatively large increase in the voltage or current in an electrical circuit or cable. Also called transient.
    Suspended CeilingA ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: Drop Ceiling, Suspended Ceiling.
    Sweep TestA method to determine the frequency response of a cable by generating an RF voltage whose frequencies varied at a rapid constant rate over a given range.
    Switchboard CableA cable used within and between the central office main frames and the switchboard.
    Take-UpThe process of accumulating wire or cable onto a reel, bobbin, or some other type of pack. Also, the device for pulling wire or cable through a piece of equipment or machine.
    Tank TestA voltage dielectric test in which the test sample is submerged in water and voltage is applied between the conductor and water as gro u n d .
    TapeA relatively narrow woven or cut strip of fabric, paper, or film material.
    Tape WrapA spirally applied tape over an insulated or uninsulated wire .
    Taped InsulationInsulation of helically wound tapes applied over a conductor or over an assembled group of insulated conductors.
    TapingProcess of insulating continuous length, large diameter wires with tape of non-extrudable materials.
    TarnishA term used to describe a discolored or stained conductor or shield wire caused by exposure to the atmosphere .
    TBTerminal Block.
    Tear StrengthThe force required to initiate or continue a tear in a material under specified conditions.
    TeflonDuPont’s Company trade name for fluorocarbon resins. FEP, PFA and TFE are typical materials.
    TefzelDuPont’s trade name for a fluoro carbon material typically used as a wire wrap insulation.
    TelecommunicationsThe communication of information over some distance, including interbuilding and intrabuilding distances.
    Telecommunications Grounding BusbarA common point of connection for telecommunications system and bonding to ground, which is located in the telecommunications closet or equipment room.
    Telecommunications InfrastructureA collection of those telecommunications components excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.
    Telemetry CableCable used for transmission of information from instruments to the peripheral recording equipment.
    Temperature RatingThe maximum temperature at which an insulating material may be used in continuous operation without loss of its basic properties (i.e. operating, overload, short circuit). The minimum temperature for safe handling.
    Tensile StrengthThe pull stress required to break a given specimen. Measured in pounds per square inch. Also referred to as Ultimate Tensile Strength.
    Tension MemberA member included in a fiber cable to add tensile strength.
    Terminal(1) A point at which information may enter or leave a communications network; (2) The input-output associated equipment; (3) A device by means of which wires may be connected to each other.
    TerminalsMetal wire termination devices designed to handle one or more conductors, and to be attached to a board bus or block with mechanical fasteners or clipped on.
    Terminating CableA multi-paired cable usually with tinned conductors and always with fire resistant insulation that is used primarily between the cable vault and the main distributing frame.
    Test LeadA flexible, insulated lead wire used for making tests, connecting instruments to a circuit temporarily or for making temporary electrical connections.
    Textile BraidAny braid made from threads of cotton, silk or synthetic fibers.
    Thermal AgingExposure to a thermal condition or programmed series of conditions for predescribed periods of time.
    Thermal RatingThe maximum and/or minimum temperature at which a material will perform its functions without undue degradation.
    Thermal ShockA test to determine the ability of a material to withstand heat and cold by subjecting it to rapid and wide changes in temperature .
    ThermocoupleA device consisting of two dissimilar metals in physical contact, which when heated will develop an emf output.
    Thermocouple ElementA thermocouple designed to be used as part of an assembly, but without associated parts such as the terminal block, connecting head, or protecting tube.
    Thermocouple Extension CableA cable comprised of one or more twisted thermocouple extension wires under a common sheath.
    Thermocouple Extension WireA pair of wires of dissimilar alloys having such emf temperature characteristics complementing the thermocouple which is intended to be used, such that when properly connected, allows the emf to be faithfully transmitted to the reference junction.
    Thermocouple Lead WireAn insulated pair of wires used from the couple to a junction box.
    Thermocouple WireA two conductor cable, each conductor employing a dissimilar metal, made up especially for temperature measurements.
    ThermoplasticA material that can be softened repeatedly by heating and hardened by cooling through a temperature range characteristic of the plastic and that in the softened state can be shaped by molding or extrusion.
    ThermosetA plastic material which is crosslinked by a heating process known as curing. Once cured, thermosets cannot be reshaped.
    ThermosettingTerm describing insulation that will not resoften or distort from its formed shape by heating until a destructive t e m p e r a t u re is re a c h e d .
    Three Conductor CableThree insulated conductors assembled with other necessary cable components (shield, filler, etc.) to form a core, protected by an overall jacket.
    Three-Phase CurrentCurrent delivered through three wires, with each wire serving as a return for the other two.
    Three-Phase Three-Wire SystemAn alternating current supply system comprising three conductors over which three-phase power is sent.
    Three-Wire SystemA DC or single-phase AC system comprising three conductors, one of which is maintained at a potential midway between the potential of the other two.
    Tight BufferType of cable construction whereby each glass fiber is tightly buffered by a protective thermoplastic coating to a diameter of 900 µm. Increased buffering provides ease of handling and connectorization.
    Time-Division Multiplex (TDM)The process or device by which more than one signal can be sent over a single channel by using different time intervals for the different signals. This may be done by varying the pulse duration, pulse amplitude and pulse position.
    Tin Overcoat (TOC)Tinned copper wire, stranded, then coated with pure tin.
    Tinned CopperTin coating added to copper to aid in soldering and inhibit corrosion.
    Tinned WireCopper wire that has been coated with a layer of tin or solder to simplify soldering.
    TinselA type of electrical conductor comprised of a number of tiny threads, each thread having a fine, flat ribbon of copper or other metal closely spiraled about it. Used for small size cables requiring limpness and extra-long flex life.
    Tinsel WireA low voltage, stranded wire where each strand is a very thin conductor ribbon spirally wrapped around a textile yarn. Insulation is generally a textile braid. Intended usage is for severe flexing.
    TopcoatBare (untinned) copper wire stranded, then coated with pure tin.
    TopologyThe physical or logical arrangement of a telecommunications system.
    Total Internal ReflectionThe total reflection that occurs when light strikes an interface at angles of incidence greater than the critical angle.
    TracerA means of identifying polarity.
    Tracer StripeWhen more than one color coding stripe is required, the first, or widest, stripe is the base stripe, the other, usually narrower stripes, being termed tracer stripes.
    TransducerA device for converting mechanical energy to electrical energy.
    Transfer ImpedanceFor a specified cable length, transfer impedance is defined as the ratio of internal longitude in a voltage to external current flow on the cable shield. Transfer impedance is used to determine shield effectiveness against both the ingress and egress of
    Transition PointA location in the horizontal cabling where flat undercarpet cable connects to round cable.
    TransmissionTransfer of electric energy from one location to another through conductors or by radiation or induction fields.
    Transmission CableTwo or more transmission lines. See Transmission Line.
    Transmission LineA signal-carrying circuit with controlled electrical characteristics used to transmit high-frequency or narrow-pulse signals.
    Transmission LossThe decrease or loss in power during transmission of energy from one point to another. Usually expressed in decibels.
    Transmission MediaThe various types of wire and optical fiber cable used for transmitting voice or data signals. Typically, wire cable includes twisted pair, coaxial, and twinaxial. Optical fiber cable includes single, dual, quad stranded, and ribbon.
    TransmitterThe electronic package that injects an electrical signal or light signal over the transmission medium.
    TransparentTransmitting rays of light so that objects can be seen through the material.
    TranspositionInterchanging the relative positions of wires to neutralize the effects of induction to or from other circuits or, to minimize interference pickup by the lead-in during reception.
    TrayA cable tray is a unit or assembly of units or sections and associated fittings, made of noncombustible materials forming a rigid structural system used to support cables.
    Tray CableA factory-assembled multi-conductor or multi-pair control, signal or power cable specifically approved under the National Electrical Code and/or the Canadian Electrical Code for installation in trays.
    TriadThree insulated wires of a single circuit forming a unit. (Two or more units are cabled to form a multi-triad cable.)
    TriaxialA three-conductor cable with one conductor in the center, a second circular conductor shield concentric with the first, and third circular conductor shield insulated from and concentric with the first and second, usually with insulation, and over a braid
    Triaxial CableA cable construction having three coincident axes, such as conductor, first shield and second shield, all insulated from one another.
    Triple (Triad)A cable consisting of three insulated single conductors twisted together.
    Triple CableA cable composed of three insulated single conductors and one bare conductor all twisted together. It may or may not have a common covering of binding.
    TriplexA cable composed of three insulated single conductor cables twisted together.
    Triplexed CableThree individual cables twisted together.
    True ConcentricA stranded wire or twisted cable in which each successive layer has a reversed direction of lay from the preceding layer.
    Trunk CableIn telecommunication or CATV systems, the transmission cable from the head end (signal pickup) to the trunk amplifier. Also called a Trunk Cable.
    TubingA tube of extruded non-supported plastic or metallic material.
    Twin CableA pair of insulated conductors twisted, sheathed, or held together mechanically and not identifiable from each other in a common covering.
    Twin CoaxialA configuration containing two separate complete coaxial cables laid parallel or twisted around each other in one complex .
    Twin Coaxial CableA single cable consisting of two separate coaxial cables laid adjacent and parallel or twisted together.
    Twin LineA transmission line which has a solid insulating material, in which the two conductors a replaced in parallel to each other.
    TwinnerA device for twisting together two conductors.
    Twisted PairsA cable composed of two small insulated conductors twisted together without a common covering.
    Twisted TriadAny three individually insulated conductors which are twisted together.
    ULAn abbreviation for Underwriters’ Laboratories, a non-profit independent organization, which operates a listing service for electrical and electronic materials and equipment. (Canadian counterpart is CSA).
    Unbalanced CircuitA transmission line in which voltages on the two conductors are unequal with respect to ground, i.e., a coaxial cable.
    Unbalanced LineA transmission line in which voltages on the two conductors are unequal with respect to ground.
    Unidirectional Concentric StrandingStranding where each successive layer has a different lay length thereby retaining a circular form without migration of strands from one layer to another.
    Unidirectional StrandingA term denoting that, in a stranded conductor, all layers have the same direction of lay.
    UnilayA conductor with more than one layer of helically laid wires with the direction of lay and length of lay the same for all layers.
    Unilay StrandA conductor constructed with a central core surrounded by more than one layer of helically-laid wires, with all layers having a common length and direction of lay.
    Unilay StrandingA bunched construction having 19, 27, 37, or any number of strands which might be found in a concentric stranding.
    UTEApproval agency for France; Union Technique de l’Electricite.
    V W-1A flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test (formerly designated FR-1).
    ValleyAny void between the insulated conductors of a cable or between a cable core and its covering. See also interstice.
    VDEWest Germany approval agency.
    Velocity of Propagation (VP)The speed of an electrical signal down a length of cable compared to speed in free space expressed as a percent. It is the reciprocal of the square root of the dielectric constant of the cable insulation.
    VHFAbbreviation for very high frequency, 30 to 300 MHz.
    Video Pair CableA transmission cable containing low-loss pairs with an impedance of 125 ohms. Used for TV pick ups, closed circuit TV, telephone carrier circuits, etc.
    Voice FrequencyAny of the frequencies that are audible to the human ear. For telephone transmission the range is generally from 300 to 3,400 Hz.
    VoltThe standard unit of electromotive force or electrical pressure. One volt is the amount of pressure that will cause one ampere of current to flow through one ohm of resistance.
    VoltageThe term most often used in place of electromotive force, potential difference or voltage drop to designate the electric pressure that exists between two points and is capable of producing a current when a closed circuit is connected between two points.
    Voltage BreakdownTest to determine voltage at which insulation fails at a given temperature and time.
    Voltage DropThe voltage developed across a component or conductor by the current in the resistance or impedance of the component or conductor.
    Voltage Rating(1) The highest voltage that can be continuously applied to a wire in conformance with the standard or specification; ( 2) The system voltage printed on the wire or cable.
    Voltage Standing Wave Ratio (VSWR)The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of a mismatched radio frequency transmission line.
    Volume ResistivityThe electrical resistance between opposite faces of a one cm. cube of insulating material, commonly expressed in ohms-centimeter.
    VSWRAbbreviation for volume standing wave ratio.
    VulcanizationA chemical reaction in which the physical properties of an elastomer are changed by reacting it with sulfur or other crosslinking agents.
    Wall ThicknessThe thickness of the applied insulation or jacket.
    WAN (Wide Area Network)A network spanning a broad geographical area, providing data communications between computers and peripherals and switching equipment.
    Water AbsorptionRatio of the weight or water absorbed by a material to the weight of the dry material.
    Waterblocked CableA cable constructed with no internal voids in order to allow no longitudinal water passage under a given pressure .
    Watertight CableA cable specially constructed with no internal voids in order to allow no longitudinal water passage under a given pressure .
    WattA unit of electrical power. One watt is equivalent to the power represented by one ampere of current under a pressure of one volt in a D.C. circuit.
    Wave FormA graphical representation of a varying quantity. Usually, time is represented on the horizontal axis, and the current or voltage value is represented on the vertical axis.
    WavelengthThe distance, measured in the direction of propagation, of a repetitive electrical pulse or waveform between two successive points.
    WettingThe ability of a material to absorb moisture .
    Wire and Cable MarkerIdentification marking of wire and cable.
    Wire and Cable Tying, Clamping, and Harnessing DevicesTying tapes, lacing cords, and flexible sleevings which are used for wire and cable bundling, harnessing, and holding. Other devices include plastic ties or clamps, spiral-cut plastic tubing, and plastic U-shaped trays or ducts.
    Wire and Lead CuttersTools for cutting range from plier type cutters to semiautomatic or fully automatic machines integrated with other wire processing operations such as stripping, forming, and terminating.
    Wire GaugeA measure of the diameter or sizes of wires. The sizes are expressed by numbers.
    Wire NutA closed end splice that is screwed on instead of crimped.
    Wire Wrapped ConnectionA solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool.
    Wire Wrapping ToolsPortable electric tools and automatic stationary machines used to make solderless wrapped connections of wires to terminals.
    Wiring ClosetAn enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling. The closet is the recognized location of the cross-connect between the backbone and horizontal facilities.
    Work Area (Work Station)A building space where the occupants interact with telecommunications terminal equipment.
    Working Voltage(1) The highest voltage that can be continuously applied to a wire in conformance with the standard or specification; ( 2) The system voltage printed on the wire or cable.
    WrapperAn insulating barrier applied as a sheet or tape wrapped around a coil periphery.
    XLPCrosslinked polyethylene.
    XLPECrosslinked polyethylene.
    Yield StrengthThe minimum stress at which a material will start to physically deform without further increase in load.
    Zero-Dispersion WavelengthWavelength at which the chromatic dispersion of an optical fiber is zero. Occurs when waveguide dispersion cancels out material dispersion.