What it is:
A device used to detect faults in cable lines based on the principle of impulse reflection.
How it works:
The TDR sends a short electrical pulse into the cable. When the pulse encounters a change in impedance—such as a break, short circuit, or insulation damage—part of the signal is reflected back. By measuring the return time of the reflection and knowing the signal propagation speed, the device calculates the distance to the fault.
What it shows:
The TDR displays a reflectogram—a waveform graph showing the reflected signals from irregularities in the cable. Based on their shape, polarity, and delay, the type and location of the fault can be determined.
Application:
- Detecting conductor breaks
- Finding short circuits
- Assessing the quality of joints and terminations
- Cable route tracing (with auxiliary probes)
Advantages:
- Quick, non-destructive testing
- Accurate fault localization
- Applicable to electrical, coaxial, and twisted-pair cables
Limitations:
Less effective for high-resistance or intermittent faults, as the reflected signal may be weak or inconsistent.
