Glossary
Stability
The change in the accuracy of a measurement or piece of test equipment over a period of time
such as the calibration interval. Stability may also refer to changes in accuracy related to a
specific environmental influence such as vibration, temperature, or humidity.
TDR
Acronym for Time-Domain Reflectometer or Reflectometry. TDR instruments use a form of
closed-circuit radar to detect cable faults. A series of pulses are sent into a cable and reflected
voltage is measured as a function of time. If the velocity of propagation (Vp) is known, the length
of a cable and the distance to cable faults can be determined. TDR traces produced by step-rise
TDRs like the CT100 describe the impedance of a cable along its length and can accurately detect
a wide range of cable faults that can impair high-frequency analog/RF and digital communications
systems.
Trace Averaging
See Noise.
Velocity of Propagation (Vp)
Velocity of propagation of an electrical signal within a cable as a fraction of
c
, the speed of light in
a vacuum. Coaxial cable usually has a Vp of between 0.6 and 0.9.
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Mohr CT100 / CT100HF Operator's Manual
