The factors that affect the waveform of the cable fault tester are:
(1) The insulation material of the cable. If it is an oil-paper cable or pure cross-linked polyethylene material, the fault waveform is simple and clear; if it is a polyvinyl chloride material, which is affected by additives and has poor wave propagation characteristics, the fault waveform decays quickly, and the reflection of the fault point is difficult to identify;
(2) Whether the fault insulation resistance of the cable is less than 1000 ohms, when it is less than 1000 ohms, the reflected waveform of the fault point is relatively clear;
(3) Whether the pulse reflectometer has the function of the comparison method, the pulse reflector with the comparison method displays the waveforms of the good phase and the bad phase at the same time on the same screen, and the bifurcation point of the two waveforms is the location of the fault point;
(4) Whether the cable under test has a T-connected branch cable. If so, a TDR partner is required to apply the disconnection signal of the TDR partner at the far end of the tested trunk cable or the far end of the branch cable, so that the emission waveform of the fault point is separated from the far end of the branch cable.