5.1 This practice is consistent with a performance-based approach wherein the frequency of recalibration and instrument testing is linked to the results from continuing instrument quality control. Under the premise of this practice, a laboratory demonstrates that its instrument performance is acceptable for analyzing sample test sources.

5.2 When a laboratory demonstrates acceptable performance based on continuing instrument quality control data (that is, control charts and tolerance charts), batch QC samples (that is, blanks, laboratory control samples, replicates, matrix spikes, and other batch QC samples as may be applicable) and independent reference materials, traditional schedule-driven instrument recalibration is permissible but unnecessary.

5.3 When continuing instrument QC, batch QC, or independent reference material sample results indicate that instrument response has exceeded established control or tolerance limits, instrument calibration is required. Other actions related to sample analyses on the affected instruments may be required by the QMS.

5.4 The data obtained while following this practice will likely be stored electronically. The data remain in electronic storage, where they are readily available to produce plots, graphs, spreadsheets, and other types of displays and reports. The QMS should specify the frequency and performance of data storage backup.

1.1 This practice covers consensus criteria for the setup, calibration, and quality control of nuclear instruments. Setup establishes the operating parameters of the instrument—for example, voltage or discriminator settings. Calibrations determine the instrument’s response characteristics—for example, its counting efficiency or energy response. Quality control ensures that the performance of the instrument remains acceptable for its intended use and consistent with the performance at the time of calibration.

1.2 This practice addresses four of the most commonly used types of nuclear counting instruments: alpha-particle spectrometer, gamma-ray spectrometer, gas proportional counter, and liquid scintillation counter.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions that are provided for information only and are not considered standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.