Question

How often should the constancy of a dose calibrator be checked and how is it done?

A. Monthly, by measuring a known activity source and comparing it to the expected value.
B. Quarterly, by comparing the measurements of different radionuclide sources.
C. Annually, by performing a linearity test using a range of activity levels.
D. Biennially, by comparing the measurements of the dose calibrator to a secondary standard.

Answer 1

The constancy of a dose calibrator is commonly checked daily using a known activity source such as Cesium-137 to compare against the expected value, with additional linearity and accuracy checks performed quarterly and annually, respectively.

Step-by-step explanation:

The constancy of a dose calibrator should be checked frequently to ensure accurate measurements of radioactivity for various applications, including medical diagnostics. The Nuclear Regulatory Commission (NRC) and various state agencies have regulations regarding the frequency of these checks, which may vary depending on the specific use and jurisdiction.

However, common practice in many facilities is to check the constancy daily or before use by measuring a known activity source, usually Cesium-137, and comparing it to its expected value. The calibrator should read within ± 10% of the known activity of this source to be considered functioning correctly. Besides daily constancy checks, linearity tests are typically performed quarterly, and accuracy checks are carried out annually using reference standards.