ASTM/ISO 51261-02

4.1 Ionizing radiation is used to produce various desired effects in products. Examples include the sterilization of medical products, processing of food, modification of polymers, irradiation of electronic devices, and curing of inks, coatings, and adhesives (1, 2) . The absorbed doses employed in these applications range from about 10 Gy to more than 100 kGy.

4.2 Regulations for sterilization of medical products and radiation processing of food exist in many countries. These regulations may require that the response of the dosimetry system be calibrated and traceable to national standards (3, 4, 5). Adequate dosimetry, with proper statistical controls and documentation, is necessary to ensure that the products are properly processed.

4.3 Proper dosimetric measurements must be employed to ensure that the product receives the desired absorbed dose. The dosimeters must be calibrated. Calibration of a routine dosimetry system can be carried out directly in a national or accredited standards laboratory by standardized irradiation of routine dosimeters. Alternatively, it may be carried out through the use of a local (in-house) calibration facility (6) or in a production irradiator. All possible factors that may affect the response of dosimeters, including environmental conditions and variations of such conditions within a processing facility, should be known and taken into account. The associated analytical instrumentation must also be calibrated.

1.1 This guide covers the basis for selecting and calibrating dosimetry systems used to measure absorbed dose in gamma-ray or X-ray fields and in electron beams used for radiation processing. It discusses the types of dosimetry systems that may be employed during calibration or on a routine basis as part of quality assurance in commercial radiation processing of products. This guide also discusses interpretation of absorbed dose and briefly outlines measurements of the uncertainties associated with the dosimetry. The details of the calibration of the analytical instrumentation are addressed in individual dosimetry system standard practices.

1.2 The absorbed-dose range covered is up to 1 MGy (100 Mrad). Source energies covered are from 0.1 to 50 MeV photons and electrons.

1.3 This guide should be used along with standard practices and guides for specific dosimetry systems and applications covered in other standards.

1.4 Dosimetry for radiation processing with neutrons or heavy charged particles is not covered in this guide.

1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.