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1、BRITISH STANDARD BS ISO 15568:1998 Practice for use of calorimetric dosimetry systems for electron beam dose measurements and dosimeter calibrations ICS 17.240 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998 This British St
2、andard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 August 1999 BSI 03-2000 ISBN 0 580 32906 2 National foreword This British Standard reproduces verbatim ISO 15568:1998 and imp
3、lements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee NCE/2, Health physics instrumentation, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries
4、 on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British
5、Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British St
6、andard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cove
7、r, an inside front cover, pages i and ii, the ISO title page, pages ii to iv, pages 1 to 12 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since
8、 publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998 BSI 03-2000i Contents Page National forewordInside front cover Forewordiii Text of ISO 155681 Licensed Copy: sheffieldun sheffieldun, na, Sun
9、 Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998
10、 ii BSI 03-2000 Contents Page Forewordiii 1Scope1 2Referenced Documents1 3Terminology1 4Significance and Use2 5Interferences2 6Apparatus3 7Calibration Procedures5 8Dose Measurement Procedures6 9Calibration of Other Dosimeters8 10Documentation8 11Precision and Bias9 12Keywords9 Appendix X1 (Nonmandat
11、ory Information) Determination of specific heat capacity11 Appendix X2 Calorimeter suppliers11 Figure 1 Example of a Graphite Calorimeter Used at a 10-MeV Industrial Electron Accelerator (7)3 Figure 2 Example of a Water Calorimeter Used for Routine Measurements at a 10-MeV Industrial Electron Accele
12、rator (6)4 Figure 3 Example of Measurements of Temperature of a Graphite Calorimeter Before and After Irradiation Only (9)7 Figure 4 Example of On-Line Measurements of a Graphite Calorimeter (9)8 Table 1 Thickness and Size of Several Graphite Calorimeters Designed at NIST for Use at Specific Electro
13、n Energies3 Table 2 Factors Contributing to Uncertainties in the Absorbed Dose Reading of the NIST Reference Graphite Calorimeter (In Percent, at a 95 % Confidence Level) (1,7)9 Table 3 Factors Contributing to Uncertainties in the Absorbed Dose Reading of Routine Polystyrene Calorimeters from Rise H
14、igh Dose Reference Laboratory (In Percent, at a 95 % Confidence Level) (13)10 References12 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998 BSI 03-2000iii Foreword ISO (the International Organization for Standardization) is
15、a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represent
16、ed on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards a
17、dopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 15568 was prepared by the American Society for Testing and Materials (ASTM) S
18、ubcommittee E10.01 (as E 1631-96) and was adopted, under a special “fast-track procedure”, by Technical Committee ISO/TC 85, Nuclear energy, in parallel with its approval by the ISO member bodies. A new ISO/TC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review
19、 the voting comments from the ISO “Fast-track procedure” and to maintain these standards. The USA holds the convenership of this working group. International Standard ISO 15568 is one of 20 standards developed and published by ASTM. The 20 fast-tracked standards and their associated ASTM designation
20、s are listed below: ISO Designation ASTM DesignationTitle 15554E 1204-93Practice for dosimetry in gamma irradiation facilities for food processing 15555E 1205-93Practice for use of a ceric-cerous sulfate dosimetry system 15556E 1261-94Guide for selection and calibration of dosimetry systems for radi
21、ation processing 15557E 1275-93Practice for use of a radiochromic film dosimetry system 15558E 1276-96Practice for use of a polymethylmethacrylate dosimetry system 15559E 1310-94Practice for use of a radiochromic optical waveguide dosimetry system 15560E 1400-95aPractice for characterization and per
22、formance of a high-dose radiation dosimetry calibration laboratory 15561E 1401-96Practice for use of a dichromate dosimetry system 15562E 1431-91Practice for dosimetry in electron and bremsstrahlung irradiation facilities for food processing 15563E 1538-93Practice for use of the ethanol-chlorobenzen
23、e dosimetry system 15564E 1539-93Guide for use of radiation-sensitive indicators 15565E 1540-93Practice for use of a radiochromic liquid dosimetry system 15566E 1607-94Practice for use of the alanine-EPR dosimetry system Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43 GMT+00:00 2006,
24、 Uncontrolled Copy, (c) BSI BS ISO 15568:1998 iv BSI 03-2000 ISO Designation ASTM DesignationTitle 15567E 1608-94Practice for dosimetry in an X-ray (bremsstrahlung) facility for radiation processing 15568E 1631-96Practice for use of calorimetric dosimetry systems for electron beam dose measurements
25、and dosimeter calibrations 15569E 1649-94Practice for dosimetry in an electron-beam facility for radiation processing at energies between 300 keV and 25 MeV 15570E 1650-94Practice for use of cellulose acetate dosimetry system 15571E 1702-95Practice for dosimetry in a gamma irradiation facility for r
26、adiation processing 15572E 1707-95Guide for estimating uncertainties in dosimetry for radiation processing 15573E 1818-96Practice for dosimetry in an electron-beam facility for radiation processing at energies between 80 keV and 300 keV Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 03:40:43
27、 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998 BSI 03-20001 1 Scope 1.1 This practice covers the preparation and use of semi-adiabatic calorimeters for measurement of absorbed dose in graphite, water, or polystyrene when irradiated with electrons. The calorimeters are either transport
28、ed by a conveyor past a scanned electron beam or are stationary in a broadened beam. It also covers the use of these calorimeters to calibrate dosimeter systems in electron beams intended for radiation processing applications. 1.2 This practice applies to electron beams in the energy range from 4 to
29、 12 MeV. 1.3 The absorbed dose range depends on the absorbing material and the irradiation and measurement conditions. Minimum dose is approximately 100 Gy and maximum dose is approximately 50 kGy. 1.4 The averaged absorbed dose rate range shall generally be greater than 10 Gys1, but depends on the
30、same conditions as above. 1.5 The temperature range for use of these calorimeters depends on the thermal resistance of the materials and on the calibration range of the temperature sensor. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It i
31、s 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. 2 Referenced Documents 2.1 ASTM Standards: E 170, Terminology Relating to Radiation Measurements and Dosimetry1). E 666, Prac
32、tice for Calculating Absorbed Dose from Gamma or X Radiation1). E 668, Practice for Application of Thermoluminescence-Dosimetry (TLD) Systems for Determining Absorbed Dose in Radiation-Hardness Testing of Electronic Devices1). E 1261, Guide for Selection and Calibration of Dosimetry Systems for Radi
33、ation Processing1). E 1431, Practice for Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing1). E 1649, Practice for Dosimetry in an Electron Beam Facility for Radiation Processing at Energies Between 300 keV and 25 MeV 1). E 1707, Guide for Estimating Uncertainties i
34、n Dosimetry for Radiation Processing1). 2.2 International Commission on Radiation Units and Measurements (ICRU) Reports:2) ICRU Report 33, Radiation Quantities and Units. ICRU Report 34, The Dosimetry of Pulsed Radiation. ICRU Report 35, Radiation Dosimetry: Electron Beams with Energies Between 1 an
35、d 50 MeV. ICRU Report 37, Stopping Powers for Electrons and Positrons. ICRU Report 44, Tissue Substitutes in Radiation Dosimetry and Measurements. 3 Terminology 3.1 Definitions 3.1.1 adiabatic, adj no heat exchange with the surroundings 3.1.2 calorimeter, n assembly consisting of calorimetric body (
36、absorber), thermal insulation, and temperature sensor with wiring 3.1.3 calorimetric body, n the mass of material absorbing radiation energy and whose temperature is measured 3.1.4 endothermic reaction, n a chemical reaction that consumes energy 3.1.5 exothermic reaction, n a chemical reaction that
37、releases energy 3.1.6 heat defect (thermal defect), n the amount of energy released or consumed by chemical reactions caused by the absorption of radiation energy 3.1.7 specific heat capacity, n the amount of energy required to raise a specified mass of material by a specified temperature 3.1.8 ther
38、mistor, n electrical resistor with a well-defined relationship between resistance and temperature 1) Annual Book of ASTM Standards, Vol 12.02. 2) Available from the Commission on Radiation Units and Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814. Licensed Copy: sheffieldun sheffield
39、un, na, Sun Nov 26 03:40:43 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 15568:1998 2 BSI 03-2000 3.1.9 thermocouple, n a junction of two metals producing an electrical voltage with a well-defined relationship to temperature 3.2 For additional terms, see Terminology E 170 and ICRU Report 33. 4
40、Significance and Use 4.1 This practice is applicable to the standardization of absorbed dose in electron beams, the qualification of electron irradiation facilities, dosimetry intercomparisons between laboratories, periodic checks of operating parameters of electron processing facilities, and calibr
41、ation of other dosimeters in electron beams. NOTE 1For additional information of the use of dosimetry in electron accelerator facilities, see Practices E 1431 and E 1641, ICRU Reports 34 and 35, and Refs 13.3) 4.2 Graphite calorimeters provide a reliable means of measuring absorbed dose in graphite.
42、 The dose measurement is based on the measurement of the temperature increase in a graphite absorber irradiated by an electron beam. 4.2.1 For graphite for which the specific heat capacity is known, no calibration of the graphite calorimeter is needed. 4.2.2 The absorbed dose in other materials irra
43、diated under equivalent conditions may be calculated. Procedures for making such calculations are given in Practices E 666 and E 668, Guide E 1261, and Reference (1). 4.2.3 The average absorbed dose in the graphite volume is measured. Dose gradients may occur in this volume and may have to be consid
44、ered when estimating dose in other materials. 4.3 Water calorimeters provide a reliable means of measuring absorbed dose in water. The dose measurement is based on the measurement of the temperature increase in a volume of water, for example, a water-filled polystyrene petri dish. 4.3.1 The response
45、 of the water calorimeters should be calibrated by comparison with graphite calorimeters irradiated under precisely the same conditions. 4.3.2 The average dose in the water calorimeter is evaluated. Dose gradients may occur in this volume and may need to be considered when estimating dose in other m
46、aterials. 4.4 Polystyrene calorimeters provide a reliable means of measuring absorbed dose in polystyrene. The dose measurement is based on the measurement of the temperature increase in a volume of polystyrene. 4.4.1 The response of the polystyrene calorimeters should be calibrated by comparison wi
47、th graphite calorimeters irradiated under precisely the same conditions. 4.4.2 The average dose in the polystyrene volume is evaluated. Dose gradients may occur in this volume and may need to be considered when estimating dose in other materials. 4.4.3 Polymeric materials other than polystyrene may
48、be used for calorimetric measurements. Polystyrene is used because it is known to be resistant to radiation (4) and because no exo- or endothermic reactions are taking place (5). 5 Interferences 5.1 Extrapolation The calorimeter designs described in this practice are usually not strictly adiabatic,
49、because of the exchange of heat with the surroundings or within the calorimeter assembly. The maximum temperature reached by the calorimetric body is different from the temperature that would have been reached in the absence of that heat exchange. The temperature drifts before and after irradiation are extrapolated to the midpoint of the irradiation period in order to determine the true temperature increase due to the absorption of radiation energy. 5.2 Heat defect Chemical reactions in irradiated water and other materials (resulting in what is called t