The calibration and irradiation of instruments that measure x-rays and gamma-rays are performed in terms of the physical quantity air-kerma. The calibrations listed in the NIST Special Publication 250 Calibration Services Users Guide as calibrations 46010C through 46050S. The process for establishing calibration or correction factors for radiation detectors, charge sensitivity tests for high-gain electrometers, and irradiations of passive dosimeters is explained in this document. Calibrations are performed by comparing the instrument to a NIST primary standard, which include four free-air chambers for x-rays and cavity ionization chambers for cesium-137 (137Cs) and colbolt-60 (60Co) gamma rays. Details of the design and use of these standards are presented in this document, as well as, a description of the quality assurance checks, which are performed to assure the constancy of the standards and the accuracy of the calibrations and irradiations. The overall uncertainty with a significance of a 95% confidence limit is given as 0.9% for the air-kerma rate in the NIST beams, 1% for the calibration of a cable-connected chamber and irradiation of passive dosimeters, and 1.5% for the calibration of a condenser chamber.

Cover title. EPA project officer: Lillian G. Bradley. "Author(s): Larry Sorrels and Lillian Bradley"--Tech. rep. data. "September 2000." Includes bibliographical references (leaf 17). "EPA-452/D-00-005."