1 This practice covers the preparation, handling, testing, and procedure for using the ethanol-chlorobenzene dosimetry system to measure absorbed dose in materials irradiated by photons and electrons in terms of absorbed dose in water. The system consists of a dosimeter and appropriate analytical instrumentation. For simplicity, the system will be referred to as the ECB system. It is classified as a reference-standard dosimeter and is also used as a routine dosimetry system (see ISO/ASTM Guide 51261).
2 This practice describes the titration analysis as a stan-dard readout procedure for the ECB dosimeter. Other appli-cable readout methods (spectrophotometric, oscillometric) are described in Annex Al and Annex A2.
3 This practice applies only to gamma rays, X rays, and high-energy electrons.
4 This practice applies provided the following are satis-fied:
4.1 The absorbed dose range shall be from 10 Gy to 2 MGy (1).
4.2 The absorbed dose rate does not exceed 10 Gy s(2).
4.3 For radionuclide gamma-ray sources, the initial pho-ton energy shall be greater than 0.6 MeV. For bremsstrahlung photons, the initial energy of the electrons used to produce the bremsstrahlung photons shall be equal to or greater than 2 MeV. For electron beams, the initial electron energy shall be equal to or greater than 4 MeV (3) (see ICRU Reports 34 and 35).
Note 1—The lower limits of electromagnetic radiation energy given are appropriate for a cylindrical dosimeter ampoule of 12-mm diameter. Corrections for dose gradients across an ampoule of that diameter or less are not required. The ECB system may be used at energies of incident electrons lower than 4 MeV by employing thinner (in the beam direction) dosimeter containers (see ICRU Report 35). The ECB system may also be used at X-ray energies as low as 120 kVp (4). In this range of photon energies the effect caused by the wall is considerable.
4.4 The irradiation temperature of the dosimeter should be within the range from -40℃ to 80℃.
Note 2—The temperature dependence of dosimeter response is known only in this range. For use outside this range, the dosimetry system should be calibrated for the required range of irradiation temperatures.
4.5 The effects of size and shape of the irradiation vessel on the response of the dosimeter can adequately be taken into account by performing the appropriate calculations using
cavity theory (5).
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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.
note: 2 The boldface numbers in parentheses refer to the bibliography at the end of this practice.
ISO/ASTM 51538:2002 history
2017ISO/ASTM 51538:2017 Practice for use of the ethanol-chlorobenzene dosimetry system
2009ISO/ASTM 51538:2009 Practice for use of the ethanol-chlorobenzene dosimetry system
2002ISO/ASTM 51538:2002 Practice for use of the ethanol-chlorobenzene dosimetry system