ASTM/ISO 51275-04

4.1 The radiochromic film dosimetry system provides a means of determining absorbed dose in materials. Under the influence of ionizing radiation, chemical reactions take place in the radiochromic film creating or enhancing, or both, optical absorption bands. Absorbance is determined within these radiation-induced absorption bands using a spectrophotometer or photometer (See 5.1.2).

4.2 In the application of a specific dosimetry system, absorbed dose is determined by use of a calibration curve traceable to national or international standards.

4.3 The absorbed dose determined is usually specified in water. Absorbed dose in other materials may be determined by applying conversion factors. This is discussed in ISO/ASTM Guide 51261.

NOTE 1 - For comprehensive discussion of various dosimetry methods applicable to the radiation types and energies discussed in this practice, see ICRU Reports 14, 17, 34, and 35.

1.1 This practice covers the procedures for handling, testing, and using a radiochromic film dosimetry system to measure absorbed dose in materials irradiated by photons or electrons in terms of absorbed dose in water.

1.2 This practice applies to radiochromic film dosimeters that can be used within part or all of the specified ranges as follows:

1.2.1 The absorbed dose range is 1 Gy to 100 kGy.

1.2.2 The absorbed dose rate is 1 x 10^-2 to 1 x 10¹³ Gy/s (1-4).

1.2.3 The radiation energy range for both photons and electrons is 0.1 to 50 MeV.

1.2.4 The irradiation temperature range is -78 to +60°C.

1.3 This practice applies to radiochromic films of various formats, including small pieces used to measure a single dose value, strips used for one-dimensional dose-mapping, and sheets used for two-dimensional dose-mapping. Three-dimensional dose-mapping may be achieved by proper placement of any of these formats.

1.4 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.