The Illustrated Dictionary of Electronics - Loscha

terrestrial magnetism • texture sensing 679terrestrial magnetism See EARTH’S MAGNETICFIELD.tertiary coil A third winding (see TERTIARYWINDING).tertiary winding A third winding on a transformeror magnetic amplifier.tesla Symbol, T. A unit of magnetic flux density; 1T = 1 weber per square meter = 10 4 gauss.Tesla coil A special type of air-core step-up transformerfor developing high voltage at radio frequencies.It consists essentially of a low-turnprimary 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 ordevice is established, (2) the value of a componentis ascertained, or (3) the behavior of a circuit ordevice is observed.test bench An equipment installation intended forthe testing, repair, or debugging of electronic devicesby a technician.test data Data used to test a computer program,including samples within limits that might be encounteredduring the program’s implementation.tester 1. See TEST INSTRUMENT. 2. A technicianwho primarily makes tests and measurements.testing window See WINDOW, 2.test instrument A device for checking the operationof a circuit or the value of a component. Thisclass of instrument is usually less accurate thanmeasurement instruments. Also see TEST SET.test lead The flexible, insulated wire attached to atest prod.test pattern A picture-and-line display on thescreen of a television picture tube, used to checksuch features as aspect ratio, linearity, contrast,etc.test point A terminal intended for connection oftest equipment in the repair or debugging of a circuit.Often, test points are labeled by the lettersTP followed by numerals (such as TP1, TP2, etc.).test probe See PROBE, 1.test prod A stick-type probe (see PROBE, 1) with aflexible, insulated lead terminating in a plug orlug for attachment to an instrument.test prodstest program In computer operations, a programdevised to check the functioning of hardware.Also called utility and test routine.test run In computer operations, using test data tocheck the operation of a program, by comparingthe results obtained thereby with what shouldideally result.test set A combination of instruments assembledon a single panel, and usually enclosed in a carryingcase, for convenience in making tests.test signal 1. A signal used for conducting a test ofa component, circuit, or system. 2. In radiotelegraphy,a special signal signifying that the transmittingstation is testing equipment. Also seeVEE 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 fortesting equalization, frequency response, headadjustment, stereo balance, etc. in an audiotaperecorder, high-fidelity sound system, computertape drive, or videocassette recorder.tetravalent See QUADRIVALENT.tetrode An electron tube in which the principalelectrodes are cathode, control grid, screen, andplate.tetrode transistor 1. A bipolar transistor with twoemitters. 2. A dual-gate field-effect transistor.Btetrode transistorCE 1 E 2TeV Abbreviation of TERA-ELECTRONVOLT.T e value The temperature at which a centimetercube of glass or ceramic exhibits 1 megohm of resistance.TE wave See TRANSVERSE ELECTRIC MODE.text editor A computer program for finding andchanging data in a file.texture map In computer graphics, the topographicalqualities of the surface of a three-dimensionalrendition. For example, the image of anorange would have a “bumpy” texture map; theimage of a peach would have a “fuzzy” texturemap.texture sensing The ability of a robotic end effectorto determine the relative smoothness or