Significance and Use
Ionizing radiation produces physical or chemical changes in many materials that can be measured and related to absorbed dose. Materials with radiation-induced changes that have been thoroughly studied can be used as dosimeters in radiation processing.
Note 3—The scientific basis for commonly used dosimetry systems and detailed descriptions of the radiation-induced interactions are given in ICRU Report 80.
Before a material can be considered for use as a dosimeter, certain characteristics related to manufacture and measurement of its response to ionizing radiation need to be considered, including:
the ability to manufacture batches of the material with evidence demonstrating a reproducible radiation-induced change,
the availability of instrumentation for measuring this change, and
the ability to take into account effects of influence quantities on the dosimeter response and on the measured absorbed-dose values.
Dosimeter/dosimetry system characterization is conducted to determine the performance characteristics for a dosimeter/dosimetry system related to its capability for measuring absorbed dose. The information obtained from dosimeter/dosimetry system characterization includes the reproducibility of the measured absorbed-dose value, the useful absorbed-dose range, effects of influence quantities, and the conditions under which the dosimeters can be calibrated and used effectively.
Note 4—When dosimetry systems are calibrated under the conditions of use, effects of influence quantities may be minimized or eliminated, because the effects can be accounted for or incorporated into the calibration method (see ISO/ASTM Guide 51261).
The influence quantities of importance might differ for different radiation processing applications and facilities. For references to standards describing different applications and facilities, see Practice E 2628
Classification of a dosimeter as a type I dosimeter or a type II dosimeter (see Practice E 2628
The dosimeter manufacturer or supplier is responsible for providing a product that meets the performance characteristics defined in product specifications, certificates of conformance, or similar types of documents. Dosimeter specifications should be developed based on dosimeter/dosimetry system characterization.
The user has the responsibility for ensuring that the dosimetry requirements for the specific applications are met and that dosimeter/dosimetry system characterization information has been considered in:
determining the suitability of the dosimeter or dosimetry system for the specific application (see Practice E 2628
selecting the calibration method (see ISO/ASTM Guide 51261),
establishing dosimetry system operational procedures (see respective dosimetry system practice listed in Practice E 2628
estimating the uncertainty components in the measured dose values (see ISO/ASTM Guide 51707).
Dosimeter/dosimetry system characterization information provided by manufacturers or suppliers, or available in the literature, should be reviewed by the user to determine the tests that should be performed prior to the use of the dosimeter or dosimetry system. Information on performance characteristics should be verified before using.
Scope
1.1 This guide provides guidance on determining the performance characteristics of dosimeters and dosimetry systems used in radiation processing.
1.2 This guide describes the influence quantities that might affect the performance of dosimeters and dosimetry systems and that should be considered during dosimeter/dosimetry system characterization.
1.3 Users of this guide are directed to existing standards and literature for procedures to determine the effects from individual influence quantities and from combinations of more than one influence quantity.
1.4 Guidance is provided regarding the roles of the manufacturers, suppliers, and users in the characterization of dosimeters and dosimetry systems.
1.5 This guide does not address how the dosimeter/dosimetry system characterization information is to be used in radiation processing applications or in the calibration of dosimetry systems.
Note 1—For guidance on the use of dosimeter/dosimetry system characterization information for the selection and use of a dosimetry system, the user is directed to Practice E 2628
Note 2—For guidance on the use of dosimeter/dosimetry system characterization information for dosimetry system calibration, the user is directed to ISO/ASTM Guide 51261.
1.6 This guide 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 and health practices and determine the applicability of regulatory limitations prior to use.
