Over deze norm
This practice covers the preparation, testing, and procedure for using the acidic aqueous silver dichromate dosimetry system to measure absorbed dose to water when exposed to ionizing radiation. The system consists of a dosimeter and appropriate analytical instrumentation. For simplicity, the system will be referred to as the dichromate system. The dichromate dosimeter is classified as a type I dosimeter on the basis of the effect of influence quantities. The dichromate system may be used as either a reference standard dosimetry system or a routine dosimetry system. This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and described a means of achieving compliance with the requirements of ASTM Practice E2628 for the dichromate dosimetry system. It is intended to be read in conjunction with ASTM Practice E2628. This practice describes the spectrophotometric analysis procedures for the dichromate system. This practice applies only to ?-rays, X-radiation/ bremsstrahlung, and high energy electrons. This practice applies provided the following conditions are satisfied: The absorbed dose range is from 2 3 103 to 5 3 104 Gy. The absorbed dose rate does not exceed 600 Gy/pulse (12.5 pulses per second), or does not exceed an equivalent dose rate of 7.5 kGy/s from continuous sources (1). For radionuclide gamma 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 8 MeV. The irradiation temperature of the dosimeter shall be above 0°C and should be below 80°C.