Time domain reflectometers are indispensable tools used for finding defects in long cable installations. They can accurately determine the exact location of the defect. You should consider investing in one if you work with a lot of cable installations.
TDRs are useful in determining defects in cables commonly found in CATV systems, distribution and telephone cables. It works like a radar where a signal is sent out and obstructions cause the signal to be reflected back. A defect like open insulation or conductor breaks will change the impedance on that spot and reflect the test signal back to the receiver. The location is computed by using the time of reflected signal takes to arrive the receiver. One good model you might want to consider is the CFL510F TDR from Megger test equipment. This tool can accurately spot defects up to 10 000 feet. It has an internal impedance matching network to match the impedance of different cable installations for accurate test results.
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