Halar (ECTFE) - Ausimont Co. trademark for Ethylene ChloroTriFluoro Ethylene.
Half-duplex - Two-way communications in which data are sent in only one direction at a time.
Halogenated - Containing halogen atoms such as chlorine, fluorine, bromine or iodine.
Halogens - Chemical elements such as chlorine and bromine that when present in a cable are released when burned. These materials can cause damage to human respiratory systems and to electrical equipment.
Hard-drawn wire - As applied to aluminum and copper, wire that has been cold drawn to final size so as to approach the maximum strength attainable.
Hardware handshaking - The ability of a modem to signal when to start or stop transmitting data. Handshaking is accomplished by sending a control signal over the modem cable rather than by issuing a software command.
Harmonic distortion - A form of interference involving the generation of unwanted signals.
Harmonic - Sinusoidal component of an AC voltage that is multiple of the fundamental waveform frequency.
Harness - An 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.
Harsh mark stripe - A non-continuous helical stripe applied to a conductor for identification.
Hazardous location - Ignitable vapors, dust, or fibers that may cause fire or explosion as defined by the NEC.
HC - Horizontal cross-connect.
HDCP (high-definition content protection) - A type of digital encryption that protects content from being copied. A subsystem of HDMI.
HDMI (high-definition multimedia interface) - The newest digital video connection on the market. HDMI supports the same high-quality video as DVI; however, it also incorporates digital audio support at many rates including surround sound, copyright protection and consumer control, all packaged into a cable with a connector about half the physical size of the original DVI connector. Utilizes a 19 pin plug for single link DVI or a 29 pin plug for dual link DVI. Works up to 75 ft. (23 m).
HDPE - High-density polyethylene.
HDTV - High-definition television.
HDX (half-duplex transmission) - Transmission in either direction but not in both directions simultaneously. Compare with FULL DUPLEX.
Headend unit - In LAN technology, an item of hardware on a single or dual cable broadband network using split frequency bands to provide multiple services.
Headend (Head-end) - A central point in broadband networks that receives signals on one set of frequency bands and retransmits them on another set of frequencies.
Heat distortion - Distortion or flow of a material or configuration due to the application of heat.
Heat seal - Method of sealing a tape wrap jacket by means of thermal fusion.
Heat shock - A test to determine stability of material by sudden exposure to a high temperature for a short period of time.
Heat sink - A device that absorbs heat.
Heater cord - A group of cable types defined in Article 400 of the NEC such as types HPD, HPN, HS, HSJ, HSJO and HSO.
Helical stripe - A continuous, colored, spiral stripe applied to a conductor for circuit identification.
Helix - Spiral winding.
Henry - A unit of inductance equal to the inductance of a current changing at the rate of one ampere per second inducing a counter electromotive force of one volt.
Hertz (Hz) - Cycles per second. A cycle that occurs once every second has a frequency of 1 hertz.
HF - High frequency.
HID - High-intensity discharge, mercury metal halide and sodium lamps.
High bond insulation - Insulation exhibiting great bond strength to the conductors.
High-split - A broadband cable system in which the bandwidth used to send toward the head-end (reverse direction) is approximately 6 MHz to 180 MHz and the bandwidth used to send from the head-end (forward direction) is approximately 220 MHz to 400 MHz The guard band between the forward and reverse directions (180 MHz to 220 MHz) provides isolation from interference.
High-temperature water and cable - Electrical wire and cables that have maximum operating temperatures of 150°C and higher.
High-tension cables - Generally unshielded high-voltage ignition wires for combustion engines, gas and oil igniters, neon signs, etc. Usually Type GTO.
High-voltage cable termination - A device used for terminating alternating current power cables having laminated or extruded insulation rated 2.5 kV and above.
High-voltage power (system voltage ratings) - A class of system voltages equal to or greater than approximately 69,000 volts or less than 230,000 volts.
Hinge cable - A cable connected between a hinged or swinging device and a stationary object.
HIPAA (Health Insurance Portability and Accountability Act ) - HIPAA provides rights and protections for participants and beneficiaries in group health plans. This can include protections for electronic transmission of health information.
Hipot - A DC high-potential test used on medium- and high-voltage cables. See DIELECTRIC STRENGTH TESTING.
HI-Z (un-terminated) - Video input of a piece of CCTV equipment, wired so as to allow the video signal to be fed to further equipment. Does not necessarily include extra sockets for the extra coaxial cables.
HL - Hazardous location. An optional rating for UL Listed Type MC cables. Article 501 of the NEC permits Type MC-HL Listed cables to be used in Class I, Division 1 Hazardous Locations.
HMWPE - High-molecular weight polyethylene.
Holding strength - Ability of a connector to remain assembled to a cable when under tension.
Hook up wire - Small wires used to hook up instruments or electrical parts, usually 12 AWG and smaller.
Horizontal (HUM) bars - Horizontal bars, alternately black and white, which extend over the entire picture. They are known as venetian-blinds. They may be stationary or move up or down. They are often caused by approximately 60 hertz interfering frequency or its harmonic frequencies.
Horizontal blanking - The blanking signal that is produced at the end of each scanning line.
Horizontal cross-connect - A cross-connect of horizontal cabling to other cabling, e.g., horizontal, backbone, equipment.
Horizontal resolution - The maximum number of individual picture elements that can be distinguished in a single scanning line.
Horizontal subsystem - The part of a premises distribution system installed on one floor that includes the cables and distribution components connecting the riser subsystem and equipment wiring subsystem to the information outlet via cross-connects.
Hot modulus - Stress at 100 percent elongation after 5 minutes of conditioning at a given temperature (normally 130°C).
Hot stamping - Method of alphanumeric coding. Identification markings are made by pressing heated tape and marking foil into softened insulation surfaces.
Hot stick - A long insulated stick having a hook at one end that is used to open energized switchgear, high-voltage equipment, etc. Allows safe separation of user and high-voltage source.
Hot tin dip - A process of passing bare wire through a bath of molten tin to provide a coating.
Housing - A metallic or other enclosure for an insulated splice.
HPD - A UL portable heater cord type. 300 V rating with two, three or four 18-12 AWG conductors with thermoset insulation and a cotton or rayon outer covering. For use in dry, no hard use locations, minimum maximum operating temperature of 90°C.
HPN - A UL portable heater cord type with parallel construction. 300 V rating with two or three 18-12 AWG conductors. Oil-resistant thermoset insulation and jacket. For use in no hard usage and damp locations, minimum maximum operating temperature of 90°C.
HRC (harmonically related carrier) - In CATV, an offset band of channel frequencies.
HSJO - A UL thermoset jacketed heater cord type. 300 V rating with two, three, or four 18-12 AWG conductors. Oil-resistant thermoset insulation and jacket. For use in non-hard usage and damp locations, minimum maximum operating temperature of 90°C.
HSPD (Homeland Security Presidential Directive) - Various directives related to security.
HSPD-12 - Requires a common ID credential for all federal employees and contractors to be used for both physical access to facilities and logical access to information systems. The PIV (personal identity verification) standard requires contact and contactless smart card technologies and biometrics.
HSRP - Hot standby router protocol.
HTCP - Home theater personal computer, separates the computer and its keyboard.
HTML (Hypertext Markup Language) - HTML is the major language of the Internet’s World Wide Web. Web sites and Web pages are written in HTML. With HTML and the World Wide Web, you have the ability to bring together text, pictures, sounds and links. HTML files are plain text files, so they can be composed and edited on any type of computer.
HTTP (Hypertext Transfer Protocol) - It’s the network protocol used to deliver virtually all files and other data (collectively called resources) on the World Wide Web, whether they’re HTML files, image files, query results or anything else. Usually, HTTP takes place through TCP/IP sockets. A browser is an HTTP client because it sends requests to an HTTP server (Web server), which then sends responses back to the client. The standard (and default) port for HTTP servers to listen on is 80, though they can use any port.
Hub - In LAN technology, it is 1. The center of a star topology network or cabling system; and 2. Same as a head end for bi-directional networks except that it is more centrally located within the network.
HV - High voltage.
HVAC - Heating, ventilation and air conditioning.
Hybrid cable - An assembly of two or more cables of different types or categories, covered by one overall sheath.
Hybrid network - A LAN with a mixture of topologies and access methods. For example, a network that includes both a token ring and a CSMA/CD bus.
Hybrid topology - A network interconnection scheme consisting of a mixture of elements of daisy chain, fully connected, hierarchical, ring and star topologies.
Hydroscopic - Readily absorbing and retaining moisture.
Hypalon - (CSP) DuPont trademark for chlorosulphonated polyethylene.
HYPOT - Registered trade name of Associated Research, Inc. for its high-voltage tester. See HIPOT.
Hysteresis - The time lag between transitions in state exhibited by a body while reacting to changes in applied forces.
Hz (hertz) - A measure of frequency or bandwidth equal to one cycle per second. Named after experimenter Heinrich Hertz.