What does 'source check' refer to in nuclear gauge operation?

In nuclear gauge operation, 'source check' specifically refers to the process of verifying that the radioactive source is securely in place and functioning properly. This is a crucial safety measure because the radioactive source is integral to the gauge’s ability to perform its measurement functions accurately.

Performing a source check ensures that the source has not been displaced or damaged, which could pose hazards not only to the operator but also to others in the vicinity. By confirming that the source is secure and operating as intended, operators can maintain compliance with safety regulations and ensure that the measurements taken by the gauge are reliable and safe.

The other options, while important aspects of overall gauge operation, do not specifically define what a 'source check' entails. Testing for calibration errors or assessing battery life involves different procedures that focus on performance and operational readiness rather than the safety and functionality of the radioactive source itself. Checking for physical damage may include a surface examination but does not address the specific function of the radioactive source within the gauge.