What is the purpose of a Time Domain Reflectometer (TDR)?

A Time Domain Reflectometer (TDR) is specifically designed to locate faults in cables, which is accomplished by measuring the reflections of electrical signals. When a signal is sent down a cable, any discontinuities or faults, such as breaks or shorts, will cause part of the signal to be reflected back towards the source. The TDR measures the time it takes for these reflections to return, which allows technicians to determine the distance to the fault based on the speed of the signal in the cable. This capability makes the TDR an invaluable tool in troubleshooting and maintaining cable systems, providing precise information about where a problem may exist without the need to visually inspect the entire length of a cable.

The other choices do not align with the primary function of a TDR. Amplifying signals is the role of amplifiers, testing signal strength is more related to spectrum analyzers, and converting analog to digital signals pertains to analog-to-digital converters rather than a TDR's fault-locating purpose.