Time Domain Reflectometry (TDR)

TDR is a measurement technique used to determine a cable's length and characteristic impedance and locate faults along the cable. TDR is sometimes referred to as cable radar because it involves analyzing signal reflections in the cable.



If a Signal traveling through a cable encounters an abrupt change in the cable's impedance, some or all of the signal is reflected back to the source. The timing, size, and polarity if the reelected signals indicate the location and nature of impedance discontinuities in the cable.