Which type of cable testing device measures signal reflections to locate faults?

The type of cable testing device that measures signal reflections to locate faults is the Time Domain Reflectometer (TDR). A TDR works by sending a pulse of electrical energy down the cable and then measuring the time it takes for the reflected signals to return. This reflection occurs when the pulse encounters a fault, such as a break, short circuit, or impedance mismatch in the cable. By analyzing the time it takes for the reflections to return and their intensity, the TDR can identify not only the presence of a fault but also its location along the cable.

This capability makes the TDR essential for troubleshooting in networking environments, allowing technicians to quickly pinpoint issues in cabling infrastructure that could affect network performance. In contrast, other devices like cable certifiers primarily assess whether a cable meets specific performance standards without directly measuring reflections, while continuity testers generally check if a circuit is complete and do not provide information on cable faults or their locations. Performance analyzers evaluate the overall performance of a network but do not focus on identifying the specific faults within the cabling.