The heating of an insulating material by AC induced internal losses; normally frequencies above 10 mHz are used.

The time rate at which electric energy is transformed into heat in a dielectric when it is subjected to a changing electric field.

The difference between 90 degrees and the dielectric phase angle. Also called dielectric phase difference.

The product of its dielectric constant and the tangent of its dielectric loss angle. Also called dielectric loss index.

The angular difference in phase between the sinusoidal alternating potential difference applied to a dielectric and the component of the resulting alternating current having the same period as the potential difference. Es­sentially, this means that when an alternating current is applied across an insulating material, the resulting alternating current passing through it (no matter how small) will be at a different phase than the voltage. The dielectric phase angle is the difference in the timing of the peak of the alternating input voltage across the dielectric and the peak of the resulting alternating current through it.

The cosine of the dielectric phase angle (or sine of the dielectric loss angle).

The voltage which an insulating material can withstand before breakdown occurs, usually expressed as a voltage gradient (such as volts per mil). Also called electric strength and disruptive gradient.

High potential test equipment is produced in both alternating current and direct current types. Equipment for measuring dielectric breakdown of electrical insulation usually consists of a 60-hertz step-up transformer, a variable primary voltage, a circuit breaker and a means of indicating the voltage applied.

A 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).

All dielectric constants are compared to air or vacuum, which is given a value of 1.0. The higher the constant number, the poorer the dielectric characteristics. A lower-quality PVC insulation may have a dielectric constant of 5.0 to 6.0 or higher. Polyethylene has a much better dielectric constant of approximately 2.0. Foamed polypropylene or polyethylene insulations have constants as low as 1.6.

In an extrusion process, a marginal zone in front of the dummy block where material gathers until it finally flows into the core.

Phenomenon 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.

Brown colored streaks in copper-bearing clad products resulting from diffusion of core-alloying constituents to the surface of the coating during thermal treatment.

A data format that uses discrete or separate physical levels to contain information.

A signal in which the data is represented by a series of discrete steps or pulses.

See Test, Dimensional Stability.

Specifications equivalent to the BS series issued by the British Standards Institution.

A two-element electronic device that allows current to flow in only one direction, serving as a rectifier.

An insulating coating applied to the conductor by passing the conductor through an applicator containing liquid insulating medium. This medium can be used for magnet wire.

A process for continuous production of copper wire rod in any re­quired length. A shaved copper rod is passed vertically upwards through a cruci­ble of molten copper, emerging as a much thicker rod that passes up a cooling tower before being led to a rolling mill for reduction to the required size as a continuous process.