Describe a common method for ensuring the integrity of a nuclear gauge's radioactive source.

Periodic leak testing is a critical method used to ensure the integrity of a nuclear gauge's radioactive source. This process involves analyzing the gauge for any signs of leakage of radioactive material from the source itself. Regular testing helps to identify and mitigate risks associated with potential exposure to radiation, thus enhancing safety for both the user and the environment.

Implementing periodic leak tests ensures that if there is a degradation in the containment of the radioactive source, it can be detected early. This practice aligns with safety regulations established by various governing bodies, which require manufacturers and users of nuclear gauges to perform such tests at defined intervals to maintain compliance and safety standards.

Visual inspections, while important for general upkeep, do not provide definitive evidence of a leak that could pose a radiation safety hazard. Replacing the source every year may not be necessary if the source is still intact and functioning properly, and calibration checks alone focus primarily on performance rather than the integrity of the source itself. Therefore, periodic leak testing stands out as the most effective approach to ensure the safety and regulatory compliance of nuclear gauges.