ASTM E1538-99e1

1.1 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 (see Guide E1261).

1.2 This practice describes the titration analysis as a standard readout procedure for the ECB dosimeter. Other applicable readout methods (spectrophotometric, oscillometric) are described in Appendixes X1 and X2.

1.3 This practice applies only to gamma rays, X rays, and high-energy electrons.

1.4 This practice applies provided the following are satisfied:

1.4.1 The absorbed dose range shall be from 10 Gy to 2 MGy (1).

1.4.2 The absorbed dose rate does not exceed 10 Gy s -1 (2).

1.4.3 For radionuclide gamma-ray sources, the initial photon 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 greater than 4 MeV (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 8 MeV by employing thinner (in the beam direction) dosimeter containers (see ICRU Report 35).

1.4.4 The irradiation temperature of the dosimeter should be within the range from -40°C to 80°C.

1.5 This standard does not purport to address all of the safety problems, 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.