18WuD2x

GIGO • glucinium 315
input to a computer will produce meaningless
output.
gilbert (William Gilbert, 1540–1603) A unit of magnetomotive
force, equal to 1.26 times the number
of ampere-turns. The SI (preferred) unit of magnetomotive
force is the ampere (symbol, A); 1
gilbert = 0.796 A.
gilbert per centimeter See OERSTED.
gimbal A suspension device whose orientation can
be changed without affecting the attitude of the
body being suspended.
gimmick 1. Colloquialism for any unnamed device.
Also see GADGET. 2. Colloquialism for any
tricky manipulation or design. 3. A low-value capacitor
made by twisting two short pieces of insulated
wire together.
gimp Colloquialism for the tinsel and cloth conductor
used in some earphone cords.
Giorgi system The meter-kilogram-second (mks)
system of units.
GJD Abbreviation of GERMANIUM JUNCTION
DIODE.
glass A hard, brittle, amorphous, and usually
transparent substance that is largely silicon dioxide.
Glass has a multitude of uses in electronics,
and there are several kinds, each having different
electrical properties. The dielectric constant
ranges from about 4 to 10; the dielectric strength
ranges from about 20 to 300 kilovolts per millimeter.
glass arm A stiffness of the wrist or forearm, somewhat
resembling writer’s cramp, sometimes experienced
by radiotelegraph operators or wire
telegraph operators after prolonged use of a hand
key.
glass bulb The glass enclosure of electron tubes
and incandescent lamps.
glass capacitor A capacitor that uses thin glass as
the dielectric, and usually has plates consisting
of metal electroplated or electrodeposited on opposite
faces of the glass. Also see MOLDED
GLASS CAPACITOR.
glass diode A semiconductor diode molded in glass.
glass electrode A probe used with a pH meter; it
consists of a thin-walled glass tube containing
potassium chloride and mercurous chloride. Also
see CALOMEL ELECTRODE.
glass envelope See GLASS BULB.
glassivation A procedure for encapsulating semiconductor
devices in glass or other dielectric material.
glass-metal seal See GLASS-TO-METAL SEAL.
glass plate capacitor See GLASS CAPACITOR.
glass shell See GLASS BULB.
glass-to-metal seal A bond between glass and
metal in electronic devices, such as vacuum tubes,
feedthrough terminals, and glass capacitors.
glass tube A vacuum tube whose elements are
housed in an evacuated glass envelope.
glide path The guidance beam used by aircraft
making instrument landings.
Runway
Transmitter
Glide-path
beam
glide-path transmitter
Plane
glide-path transmitter A radio-frequency transmitter
that produces a guidance beam for aircraft
landing purposes. The aircraft follows the beam
toward the runway.
glide slope See GLIDE PATH.
G line A microwave conductor consisting of a
round wire coated with a dielectric.
glitch 1. In a television image, a narrow, horizontal
interference bar that moves vertically. 2. A very
short and unwanted high-amplitude transient
that recurs irregularly in an electronic system.
glitter 1. In radar, an echo or set of echoes that
fluctuates rapidly in intensity because of motion
in the target. 2. A system in which moving devices
are used to confuse enemy radar systems.
gloss factor For a reflecting surface, the ratio of reflected
light in a selected direction to reflected
light in all directions.
glossmeter An instrument for determining GLOSS
FACTOR.
glow discharge The luminous electrical discharge
resulting from the passage of current through
ionized gas in a partially evacuated tube. The
color of the glow is characteristic of the particular
gas used.
glow-discharge microphone A device that produces
audio-frequency currents from the action
of sound waves in a glow-discharge tube.
glow-discharge tube A partially evacuated tube
that contains two or more electrodes. The rarefied
gas in the tube glows when a sufficient voltage is
applied to the electrodes. See DISCHARGE LAMP,
FLUORESCENT TUBE, and NEON BULB.
glow lamp See DISCHARGE LAMP.
glow modulator tube A gas tube whose luminous
output can be modulated by an audio input signal.
glow potential The voltage at which glow discharge
just begins in a gas-filled tube.
glow switch In fluorescent light circuits, an electron
tube containing two bimetal strips that make
mutual contact when heated by the glow discharge.
glow tube See DISCHARGE LAMP, FLUORES-
CENT TUBE, GLOW MODULATOR TUBE, NEON
BULB, and STROBOTRON.
glow voltage See BREAKDOWN VOLTAGE, 2.
glucinium See BERYLLIUM.