STM_51538-17.pdf

ISO/ASTM 51538:2017(E)Standard Practice forUse of the Ethanol-Chlorobenzene Dosimetry System1This standard is issued under the fixed designation ISO/ASTM 51538;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.1.Scope1.1 This practice covers the preparation,handling,testing,and procedure for using the ethanol-chlorobenzene(ECB)dosimetry system to measure absorbed dose to water whenexposed to ionizing radiation.The system consists of adosimeter and appropriate analytical instrumentation.Forsimplicity,the system will be referred to as the ECB system.The ECB dosimeter is classified as a type I dosimeter on thebasis of the effect of influence quantities.The ECB dosimetrysystem may be used as a reference standard dosimetry systemor as a routine dosimetry system.1.2 This document is one of a set of standards that providesrecommendations for properly implementing dosimetry inradiation processing,and describes a means of achievingcompliance with the requirements of ISO/ASTM Practice52628 for the ECB system.It is intended to be read inconjunction with ISO/ASTM Practice 52628.1.3 This practice describes the mercurimetric titrationanalysis as a standard readout procedure for the ECB dosimeterwhen used as a reference standard dosimetry system.Otherreadout methods(spectrophotometric,oscillometric)that areapplicable when the ECB system is used as a routine dosimetrysystem are described in Annex A1 and Annex A2.1.4 This practice applies only to gamma radiation,X-radiation/bremsstrahlung,and high energy electrons.1.5 This practice applies provided the following conditionsare satisfied:1.5.1 The absorbed dose range is between 10 Gy and 2 MGyfor gamma radiation and between 10 Gy and 200 kGy for highcurrent electron accelerators(1,2).2(Warningthe boilingpoint of ethanol chlorobenzene solutions is approximately80 C.Ampoules may explode if the temperature duringirradiation exceeds the boiling point.This boiling point may beexceeded if an absorbed dose greater than 200 kGy is given ina short period of time.)1.5.2 The absorbed-dose rate is less than 106Gy s1(2).1.5.3 For radionuclide gamma-ray sources,the initial pho-ton energy is greater than 0.6 MeV.For bremsstrahlungphotons,the energy of the electrons used to produce thebremsstrahlung photons is equal to or greater than 2 MeV.Forelectron beams,the initial electron energy is greater than 8MeV(3).NOTE1The same response relative to60Co gamma radiation wasobtained in high-power bremsstrahlung irradiation produced by a 5 MeVelectron accelerator(4).NOTE2The lower energy limits are appropriate for a cylindricaldosimeter ampoule of 12-mm diameter.Corrections for dose gradientsacross the ampoule may be required for electron beams.The ECB systemmay be used at lower energies by employing thinner(in the beamdirection)dosimeters(see ICRU Report 35).The ECB system may also beused at X-ray energies as low as 120 kVp(5).However,in this range ofphoton energies the effect caused by the ampoule wall is considerable.NOTE3The effects of size and shape of the dosimeter on the responseof the dosimeter can adequately be taken into account by performing theappropriate calculations using cavity theory(6).1.5.4 The irradiation temperature of the dosimeter is withinthe range from 30 C to 80 C.NOTE4The temperature dependence of dosimeter response is knownonly in this range(see 5.2).For use outside this range,the dosimetrysystem should be calibrated for the required range of irradiation tempera-tures.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility 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.Specific warningsare given in 1.5.1,9.2 and 10.2.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.1This practice is under the jurisdiction of ASTM Committee E61 on RadiationProcessing and is the direct responsibility of Subcommittee E61.02 on DosimetrySystems,and is also under the jurisdiction of ISO/TC 85/WG 3.Current edition approved April 25,2017.Published June 2017.Originallypublished as ASTM E1538-93.Last previous ASTM edition E153899.ASTME153893 was adopted by ISO in 1998 with the intermediate designation ISO15563:1998(E).The present International Standard ISO/ASTM 51538:2017(E)is amajor revision of ISO/ASTM 51538:2009(E).DOI:10.1520/ISOASTM51538-17.2The boldface numbers in parentheses refer to the bibliography at the end of thispractice.ISO/ASTM International 2017 All rights reservedThis international standard was developed in accordance with internationally recognized pr