Which device is commonly used to troubleshoot existing loops that are already installed in the field?

The loop analyzer is specifically designed to troubleshoot existing loops that have been installed in the field. This device allows technicians to assess the condition of inductive loops, including their electrical characteristics and performance. With a loop analyzer, you can measure parameters such as the inductance of the loop, check for shorts or opens in the loop wiring, and evaluate the loop’s overall functionality. This information is crucial for diagnosing issues that may affect traffic signal operation and for ensuring that the loops are functioning as intended.

In contrast, a traffic signal controller is responsible for managing signal operations rather than troubleshooting loop functionality. A data logger collects data over time for analysis but does not provide real-time diagnostics of loop performance. A test light, while useful for verifying the presence of power or continuity, lacks the detailed capability needed to analyze the specific characteristics of inductive loops. Hence, the loop analyzer is uniquely suited for this troubleshooting task.