Wire produced to rigid specifications and often specially produced for a particular type and size of screw. Must be suitable for case hardening heat treatment of the screw and must have good torsional properties since the screw may have to cut its own head. See Screw Wire.

Designation for super high frequency.

A metallic layer placed around an insulated conductor or group of conductors to prevent electrostatic or electromagnetic interference between the enclosed wires and external fields. For communications cable, a covering that consists of any of the following: foil wrap, continuous tube or a metal wire braid applied over a conductor or cable. See Conductor Shield or Insulation Shield.

In cables, a metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields. See Insulation Shield.

See Conductor Shield.

The physical area of a cable that is actually covered by the shielding material. It is expressed as a percentage.

Percentage of the surface area of cable core insulation covered by the shield. Also called Shield Percentage.

The relative ability of a shield to screen out undesirable signals.

A transmission line whose elements confine propagated radio waves to an essentially finite space inside a tabular conducting surface called the sheath, thus preventing the line from radiating radio waves.

See Shield Coverage Percent.

A shield of interwoven small wires.

An electrically conducting layer to provide a smooth surface in intimate contact with the insulation outer surface. Used to eliminate electrostatic charges external to the shield, and to provide a fixed known path to ground. See Insulation Shield.

The insulation shielding system whose current carrying component is thin metallic tapes, now normally used in conjunction with a conducting layer of tapes or extruded polymer.

5,000V and above, enclosed in a nonmagnetic conducting envelope, so constructed that substantially every point on the insulation is at ground potential or some pre-determined potential with respect to ground. Can apply to multiple conductor cable in which each single conductor is shielded or to a multiple conductor cable where the overall assembly is shielded.

An insulated conductor that has been shielded by a copper braid or tape, aluminum foil, copper foil or a semi-conductive vinyl. The purpose is to confine the electrical field.

A transmission line whose elements confine propagated radio waves to an essentially finite space inside a tabular conducting surface called the sheath, thus preventing the line from radiating radio waves.

A cable with a multiplicity of conductors with a metallic or non-metallic shield over the cable core.

Power cord that has serving, braid, foil or a combination of these. A served shield is made by closely wrapping wire strands around the core.

A cable in which each insulated conductor is enclosed in a conducting envelope so constructed that substantially every point on the surface of the insulation is at ground potential or at some predetermined potential with respect to ground under normal operating conditions.

Shielding is the process of wrapping material around the outside of a wire or cable to provide two major functions: to act as a barrier to keep external signals from getting in and internal signals from getting out, and to serve as a part of the electrical circuit. A third function worth noting is the physical protection it provides the internal wire or cable. Shielding is normally specified as a cable construction detail. For example, the cable may be unshielded, contain shielded pairs, have an overall aluminum/mylar tape and drain wire or even a double shield. Shielding effectiveness is very complex to measure and depends on the data frequency within the cable and the precise shield design. A shield may be very effective in one frequency range, but a different frequency may require a completely different design. System designers often test complete cable assemblies or connected systems for shielding effectiveness.