MS-QA_06-2019 rev5

ANSI/AARST MS-QA 2019 10 Radon Measurement Systems Quality Assurance Requirements For All Methods 3.2 Approved Devices and Qualified Laboratories Conformance with this standard requires the use of devices approved through a Device Evaluation Program and laboratories certified or accredited by a laboratory approval program that meets requirements as: a) established in certification requirements of the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB); or b) as required by local jurisdictions that have a program for evaluating and approving devices. 3.3 Validation of Performance 3.3.1 Laboratories and Analytical Services Performance tests are one critical verification of traceability between the recognized authority for radon concentration and field measurement results and are a component of quality systems described by international consensus standards such as ISO/IEC 17025. Blind performance or proficiency tests are important validations of the entire quality assurance program and are to be conducted in standard test atmosphere for radon ( STAR ) environments. 3.3.2 Field Operations—Blind Blanks and Spikes Informative advisory —When field blanks and field spikes are processed at an independent analysis laboratory, they should be treated and labeled as other returned detectors and are not to be identified as blanks or spikes to the analyst because the objective of field QC is to monitor the stability of field operations and procedures. If there are more restrictive requirements, including those by credentialing authorities that may require the demonstration of a minimum proportion of QC detectors and chain of custody, then that authority supersedes this standard. 3.4 Measurement System Calibrations and Evaluations To comply with this standard, measurement devices cannot be used or marketed for use outside the ranges of temperature, relative humidity and atmospheric pressure or integrated radon concentrations greater than or less than those for which the specific device type has been: a) evaluated for capacity to achieve stable, in-control response or readings within warning and control limits established herein, which may include using the physical principles of the device and theoretical extrapolations based on the device design, and b) calibrated in a manner to support expectations of in-control response or readings within warning and control limits established herein across the ranges of temperature, relative humidity, atmospheric pressure and integrated radon concentrations specified for use in product instructions. If results are reported for exposures conducted outside the ranges specified for use in product instructions, a caveat is to be included in the report with a description of concerns that were observed by the QP or in accordance with the analyst’s quality policies. If there are documented evaluations, such as from the manufacturer, demonstrating the lack of effect of an interference such as temperature or relative humidity, and such evaluation reports are available to auditors or other credentialing authorities (subject to confidentiality agreements), then calibration for these devices does not need to include exposures in different magnitudes of these interferences. Calibration is conducted by exposing a set of identical devices in a standard radon test atmosphere as defined in this standard. Because different methods are affected by different interferences and durations, calibration procedures will be agreed upon between the supplier of the device and the calibration facility.