18WuD2x

terrestrial magnetism • texture sensing 679
terrestrial magnetism See EARTH’S MAGNETIC
FIELD.
tertiary coil A third winding (see TERTIARY
WINDING).
tertiary winding A third winding on a transformer
or magnetic amplifier.
tesla Symbol, T. A unit of magnetic flux density; 1
T = 1 weber per square meter = 10 4 gauss.
Tesla coil A special type of air-core step-up transformer
for developing high voltage at radio frequencies.
It consists essentially of a low-turn
primary coil, through which radio-frequency (RF)
current flows, and a multiturn secondary coil,
across which the high voltage, is developed.
test A procedure consisting of one or several steps,
in which (1) the mode of operation of a circuit or
device is established, (2) the value of a component
is ascertained, or (3) the behavior of a circuit or
device is observed.
test bench An equipment installation intended for
the testing, repair, or debugging of electronic devices
by a technician.
test data Data used to test a computer program,
including samples within limits that might be encountered
during the program’s implementation.
tester 1. See TEST INSTRUMENT. 2. A technician
who primarily makes tests and measurements.
testing window See WINDOW, 2.
test instrument A device for checking the operation
of a circuit or the value of a component. This
class of instrument is usually less accurate than
measurement instruments. Also see TEST SET.
test lead The flexible, insulated wire attached to a
test prod.
test pattern A picture-and-line display on the
screen of a television picture tube, used to check
such features as aspect ratio, linearity, contrast,
etc.
test point A terminal intended for connection of
test equipment in the repair or debugging of a circuit.
Often, test points are labeled by the letters
TP followed by numerals (such as TP1, TP2, etc.).
test probe See PROBE, 1.
test prod A stick-type probe (see PROBE, 1) with a
flexible, insulated lead terminating in a plug or
lug for attachment to an instrument.
test prods
test program In computer operations, a program
devised to check the functioning of hardware.
Also called utility and test routine.
test run In computer operations, using test data to
check the operation of a program, by comparing
the results obtained thereby with what should
ideally result.
test set A combination of instruments assembled
on a single panel, and usually enclosed in a carrying
case, for convenience in making tests.
test signal 1. A signal used for conducting a test of
a component, circuit, or system. 2. In radiotelegraphy,
a special signal signifying that the transmitting
station is testing equipment. Also see
VEE SIGNAL.
test-signal generator A device, such as an oscillator,
for producing a signal for testing equipment
(see TEST SIGNAL, 1).
test tape A magnetic tape containing signals for
testing equalization, frequency response, head
adjustment, stereo balance, etc. in an audiotape
recorder, high-fidelity sound system, computer
tape drive, or videocassette recorder.
tetravalent See QUADRIVALENT.
tetrode An electron tube in which the principal
electrodes are cathode, control grid, screen, and
plate.
tetrode transistor 1. A bipolar transistor with two
emitters. 2. A dual-gate field-effect transistor.
B
tetrode transistor
C
E 1 E 2
TeV Abbreviation of TERA-ELECTRONVOLT.
T e value The temperature at which a centimeter
cube of glass or ceramic exhibits 1 megohm of resistance.
TE wave See TRANSVERSE ELECTRIC MODE.
text editor A computer program for finding and
changing data in a file.
texture map In computer graphics, the topographical
qualities of the surface of a three-dimensional
rendition. For example, the image of an
orange would have a “bumpy” texture map; the
image of a peach would have a “fuzzy” texture
map.
texture sensing The ability of a robotic end effector
to determine the relative smoothness or