True or False: Each calibration reference material (CRM) must be calibrated at least annually meeting standard test atmosphere requirements.

Regular calibration of calibration reference materials (CRMs) is essential in ensuring the accuracy and reliability of radon measurement devices. The requirement for annual calibration aligns with industry standards and best practices, which are designed to guarantee that the instruments used for radon measurements provide consistent and trustworthy results. Calibration helps to confirm that the measurement devices are functioning properly and are within the acceptable limits of deviation from true value.

Meeting standard test atmosphere requirements during calibration further enhances the reliability of the instruments, ensuring that they operate effectively in the environments for which they are intended. Adhering to this requirement minimizes the risk of inaccuracies in radon measurement, which can have significant health implications in residential and commercial settings.

In summary, the stipulation that each CRM must be calibrated at least annually ensures ongoing accuracy in measurement and compliance with regulatory standards, which emphasizes the importance of regular and precise calibration in radon measurement practices.