What is a common tool used for measuring cable length during verification?

A Time Domain Reflectometer (TDR) is an essential tool used for measuring cable length during verification. It works by sending a signal along the cable and measuring the time it takes for the reflection of that signal to return to the device. By knowing the speed of the signal and the time it takes for the return trip, the TDR can accurately calculate the length of the cable.

Additionally, TDRs are invaluable when identifying faults or breaks in the cable. They can provide not only distance but also detailed information about the integrity of the cable, which is crucial during the verification process.

While other tools like multimeters, oscilloscopes, and cable testers have their own specific applications, they do not measure cable length directly in the same manner that a TDR does. A multimeter is primarily used for measuring electrical properties such as voltage, resistance, and current; an oscilloscope is suited for analyzing waveforms and signals; and cable testers check cable continuity and performance but do not provide direct length measurements. Thus, the TDR stands out as the most appropriate choice for measuring cable length.