ANSI N42.13-2004 pdf download American National Standard Calibration and Usage of “Dose Calibrator” Ionization Chambers for the Assay of Radionuclides
1. Introduction The wide range of calibrator -type instruments currently being used primarily for radionuclide assay in nuclear medicine indicates the need for a standard for uniformity in measurement and test techniques. Such devices are composite systems consisting of an ionization chamber integrally coupled to appropriate electronic circuitry that converts the ionization current to a readout in units of activity. The principles of operation of the ionization chamber are well summarized in the NCRP Report No 58 [1] 1 and will not be repeated here. Wide activity range and stability are useful characteristics of ionization chambers in this application. The advantages of this type of system for radionuclide assay include ease of use and interpretation.
2. Scope
2.1 This standard covers the technique for the quantiÞcation of the activity of identiÞed radionuclides using any of a variety of ionization chambers currently available for this purpose. Application of the standard is limited to instruments that incorporate well-type ionization chambers as detectors.
2.2 This standard provides a method for obtaining measurements that are accurate to within ± 10% and reproducible to within ± 5% [usually for sources of more than 100 m Ci (3.7 ´ 10 6 Bq)]. The standard is also intended to assure continuing performance of the apparatus within these speciÞcations. For purposes of this standard, accuracy and reproducibility are described in 4.6.
3. Definitions and References
3.1 Definitions
accuracy:
Accuracy, usually described in terms of overall uncertainty, is the estimate of the overall possible deviation from the stated value. As used in this standard, the overall uncertainty is a total of the estimated error itemized in Section 5. plus the random uncertainty of the measurement.
shall:
Indicates a recommendation that is necessary or essential to meet requirements of this standard.
should:
Indicates an advisory recommendation that is to be applied when practicable.
simulated sources:
Simulated sources usually contain long-lived radionuclides, alone or in combination, that are chosen to simulate, in terms of photon or particle emission, a short-lived radionuclide of interest.