D

dB:

(1) Abbreviation for decibel; (2) The loss of a signal in a conductor expressed in decibels, denoting the ratio of the power input to output; (3) One tenth of a bel.

Delay Line:

A cable made to provide a very low velocity of propagation with a long electrical delay for transmitted signals.

Derating Factor:

A factor used to reduce a current-carrying capacity of a wire when used in environments other than that for which the value was established.

Dielectric:

(1) Any insulating medium that intervenes between two conductors and permits electrostatic attraction and repulsion to take place across it; (2) A non-conductive insulator. An "insert" material.

Dielectric Strength:

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

Durometer:

A measurement used to denote the hardness of a substance, usually an elastomer.