Which tool is commonly used to measure signal strength in telecommunications?

A signal analyzer is the appropriate tool for measuring signal strength in telecommunications. This device is specifically designed to assess various parameters of signals, including their strength, frequency, and quality. Signal analyzers can provide detailed readings and graphical representations, allowing technicians to diagnose and evaluate the performance of communication systems effectively.

In contrast, other tools listed serve different purposes: a multimeter measures electrical current, voltage, and resistance, but it is not designed for analyzing radio frequency signals. An oscilloscope is also not suited for measuring signal strength directly; it visualizes waveforms, primarily for analyzing time-dependent electrical signals. A thermometer measures temperature and has no application in signal strength measurement. Thus, the signal analyzer is the go-to instrument in the telecommunications field for this specific task.