CONVECTION
: The transmission of heat by the mass movement of the heated
air.
CORE
: A magnetic material that affords an easy path for magnetic lines of flux.
CUMULATIVE EFFECT
: Many exposures to small doses add up to a large dose.
CURRENT LIMITER
: A protective device, used in some two-fold applications as
a fuse that is designed to limit current flow in high-amperage circuits.
CYCLE
: One complete positive and one complete negative alternation of a
current or voltage.
DC VOLTAGE
: An electric current that flows in one direction only, thus it is Direct
Current.
DIELECTRIC
: A material of poor conductivity that serves as an insulator, usually
in reference to the insulating material between the plates of a capacitor. The
dielectric separates the metal plates electrically, stores an electric charge, and
undergoes polarization when subjected to an electric field.
DIFFERENCE OF POTENTIAL
: The voltage existing between two points. If a
circuit is established between the two points, a flow of electrons will result.
DIRECTLY HEATED CATHODE
: A wire or filament that is designed to emit
electrons when an electric current flows through it. The current heats the filament
to the point where electrons are emitted.
DPC:
Digital Programmer Circuit
DUMMY LOAD
: A device used at the end of a wave-guide to convert transmitted
energy into heat so no energy is radiated outward or reflected back.
DUTY CYCLE
: In a magnetron tube: The ratio of oscillating time to total time.
ELECTRODE
: The terminal at which electricity passes from one medium into
another, such as in a humidity sensor unit where the current leaves or returns to
the semi-conducting ceramic compound.
ELECTROMAGNETIC RADIATION
: The process in which waves of
electromagnetic energy are sent out into space.
ELECTROMAGNETIC WAVE
: A wave of energy propagated by the combined
interaction of electric and magnetic fields that are traveling at right angles to each
other, and to the direction of travel.
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