Test Products International 460 - Manual (Page 52)

signals.
Thermistor A resistive temperature measurement device whose resistance
decreases as the temperature increases. A thermistor is a stable,
compact and rugged two terminal ceramic-like semiconductor
bead.
Thermocouple A 2-wire temperature measurement sensor constructed of two
dissimilar metals which form a junction. Current flows from one
metal to the other in proportion to temperature. A millivolt signal
is then measured by a thermometer or other display device
temperature.
Threshold Sound levels below this point (also called Threshold Cutoff), are
excluded from dosimeter measurements. National and state
regulations determine the threshold level.
Transistor Test A function of a measuring device which can be used o check the
operation of a transistor. The leads of a transistor are inserted into
a receptacle and the meter indicates whether the device is
operational or not.
Trend Mode The function of graphing signals over time to capture problems.
Trigger Selection The basis and point at which the oscilloscope begins its tracking.
Usually selected on the basis of AC, DC, or Glitch Capture, with
slope edge, level, and sensitivity selectable.
True Power Electric power, measured in Watts.
True RMS Voltmeter A Voltmeter that measures an AC sine wave (voltage and current)
and displays the rout mean square (rms) of each waveform cycle.
Important when measuring true power, and on the non-sinusoidal
waveforms found in many circuits and controls.
Watt The unit of measure for electric power. 1-Horsepower = 746 Watts.
Zero Adjust Ability of a meter to be calibrated to a null or “zero” reference
ensuring accurate readings in all ranges.
460 User s Guide Glossary
C-6