1、BRITISH STANDARD BS ISO 15555:1998 Practice for use of a ceric-cerous sulfate dosimetry system ICS 17.240BSISO15555:1998 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authority ofthe Standards Committee andcomes into effect
2、on 15August1999 BSI 04-2000 ISBN 0 580 32914 3 National foreword This British Standard reproduces verbatim ISO 15555:1998 and implements 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 r
3、esponsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries 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.
4、 A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “Inter
5、national Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard 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
6、British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages 1 to 12, an inside back cover andabackcover. This standard has been updated (see copyrig
7、ht date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO15555:1998 BSI 04-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 15555 1ii bl
8、ankBSISO15555:1998 ii BSI 04-2000 Contents Page Foreword iii 1 Scope 1 2 Referenced Documents 1 3 Terminology 2 4 Significance and Use 3 5 Interferences 3 6 Apparatus 4 7 Reagents 4 8 Preparation of the Dosimetric Solution 4 9 Spectrophotometer Calibration 5 10 Calibration of the Dosimetric Solution
9、 6 11 Dosimetric Procedure 9 12 Calculation 9 13 Precision and Bias 10 14 Keywords 10 Appendix X1 (nonmandatory information) The electrochemical cell 11 Appendix X2 (nonmandatory information) A Procedure for preparing nominal stock solutions for the dosimeter 11 References Inside back cover Figure X
10、1.1 Electrochemical Cell 11BSISO15555:1998 BSI 04-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committ
11、ees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Int
12、ernational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member b
13、odies casting a vote. International Standard ISO 15555 was prepared by the American Society for Testing and Materials (ASTM) Subcommittee E10.01 (asE1205-93) and was adopted, under a special “fast-track procedure”, by Technical Committee ISO/TC 85, Nuclear energy, in parallel with its approval by th
14、e ISO member bodies. A new ISO/TC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review 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 15555
15、 is one of 20 standards developed and published by ASTM. The 20 fast-tracked standards and their associated ASTM designations are listed below: ISO Designation ASTM Designation Title 15554 E 1204-93 Practice for dosimetry in gamma irradiation facilities for food processing 15555 E 1205-93 Practice f
16、or use of a ceric-cerous sulfate dosimetry system 15556 E 1261-94 Guide for selection and calibration of dosimetry systems for radiation processing 15557 E 1275-93 Practice for use of a radiochromic film dosimetry system 15558 E 1276-96 Practice for use of a polymethylmethacrylate dosimetry system 1
17、5559 E 1310-94 Practice for use of a radiochromic optical waveguide dosimetry system 15560 E 1400-95a Practice for characterization and performance of a high-dose radiation dosimetry calibration laboratory 15561 E 1401-96 Practice for use of a dichromate dosimetry system 15562 E 1431-91 Practice for
18、 dosimetry in electron and bremsstrahlung irradiation facilities for food processing 15563 E 1538-93 Practice for use of the ethanol-chlorobenzene dosimetry system 15564 E 1539-93 Guide for use of radiation-sensitive indicators 15565 E 1540-93 Practice for use of a radiochromic liquid dosimetry syst
19、emBSISO15555:1998 iv BSI 04-2000 ISO Designation ASTM Designation Title 15566 E 1607-94 Practice for use of the alanine-EPR dosimetry system 15567 E 1608-94 Practice for dosimetry in an X-ray (bremsstrahlung) facility for radiation processing 15568 E 1631-96 Practice for use of calorimetric dosimetr
20、y systems for electron beam dose measurements and dosimeter calibrations 15569 E 1649-94 Practice for dosimetry in an electron-beam facility for radiation processing at energies between 300 keV and 25 MeV 15570 E 1650-94 Practice for use of cellulose acetate dosimetry system 15571 E 1702-95 Practice
21、 for dosimetry in a gamma irradiation facility for radiation processing 15572 E 1707-95 Guide for estimating uncertainties in dosimetry for radiation processing 15573 E 1818-96 Practice for dosimetry in an electron-beam facility for radiation processing at energies between 80 keV and 300 keVBSISO155
22、55:1998 BSI 04-2000 1 1 Scope 1.1 This practice covers the preparation, testing, and procedure for using the ceric-cerous sulfate dosimetry system to measure absorbed dose in water when exposed to ionizing radiation. For simplicity, the system will be referred to as the ceric-cerous system. It is cl
23、assified as a reference standard dosimetry system (seeGuide E1261). 1.2 This practice describes both the spectrophotometric and the potentiometric readout procedures for the ceric-cerous systems. 1.3 This practice applies only to rays, X-rays, and high energy electrons. 1.4 This practice applies pro
24、vided the following are satisfied: 1.4.1 The absorbed-dose range shall be between5 10 2and 5 10 4Gy (1). 1) 1.4.2 The absorbed-dose rate shall be less than10 6 Gy/s (1). 1.4.3 For radionuclide gamma-ray sources, the initial photon energy shall be greater than0.6 MeV. For bremsstrahlung photons, the
25、initial energy of the electrons used to produce the bremsstrahlung photons shall be equal to or greater than2 MeV. For electron beams, the initial electron energy shall be greater than8 MeV. NOTE 1The lower energy limits are appropriate for a cylindrical dosimeter ampoule of 12-mm diameter. Correcti
26、ons for dose gradients across an ampoule of that diameter or less are not required. The ceric-cerous system may be used at lower energies by employing thinner (in the beam direction) dosimeter containers (see ICRU Report 35). 1.4.4 The irradiation temperature of the dosimeter should be between0 and
27、62 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. 2 Refere
28、nced Documents 2.1 ASTM Standards: C 912, Practice for Designing a Process for Cleaning Technical Glasses 2) . D 941, Test Method for Density and Relative Density (Specific Gravity) of Liquids by Lipkin Bicapillary Pycnometer 3) . D 1193, Specification for Reagent Water 4) . E 170, Terminology Relat
29、ing to Radiation Measurements and Dosimetry 5) . E 178, Practice for Dealing with Outlying Observations 6) . E 275, Practice for Describing and Measuring Performance of Ultraviolet, Visible, and Near Infrared Spectrophotometers 7) . E 666, Practice for Calculating Absorbed Dose from Gamma or X Radia
30、tion 5) . E 668, Practice for Application of Thermoluminescence Dosimetry (TLD) Systemsfor Determining Absorbed Dose in Radiation-Hardness Testing of Electronic Devices 5) . E 925, Practice for the Periodic Calibration of Narrow Band-Pass Spectrophotometers 7) . E 958, Practice for Measuring Practic
31、e Spectral Bandwidth of Ultraviolet-Visible Spectrophotometers 7) . E 1026, Practice for Using the Fricke Reference Standard Dosimetry System 5) . E 1261, Guide for Selection and Application of Dosimetry Systems for Radiation Processing of Food 5) . E 1400, Practice for Characterization and Performa
32、nce of a High-Dose Gamma Radiation Dosimetry Calibration Laboratory 5) . E 1401, Practice for Use of a Dichromate Dosimetry System 5) . 1) The boldface numbers in parentheses refer to the list of references appended to this test method. 2) Annual Book of ASTM Standards, Vol 15.02. 3) Annual Book of
33、ASTM Standards, Vol 05.01. 4) Annual Book of ASTM Standards, Vol 11.01. 5) Annual Book of ASTM Standards, Vol 12.02. 6) Annual Book of ASTM Standards, Vol 14.02. 7) Annual Book of ASTM Standards, Vol 14.01.BSISO15555:1998 2 BSI 04-2000 2.2 International Commission on Radiation Units and Measurements
34、 (ICRU) Reports: ICRU Report 10b Physical Aspects of Irradiation 8) . ICRU Report 14 Radiation Dosimetry: X-Rays and Gamma Rays with Maximum Photon Energies Between0.6 and 60 MeV 8) . ICRU Report 33 Radiation Quantities and Units 8) . ICRU Report 34 The Dosimetry of Pulsed Radiation 8) . ICRU Report
35、 35 Radiation Dosimetry: Electrons with Initial Energies Between 1 and 50 MeV 8) . 3 Terminology 3.1 Definitions 3.1.1 absorbed dose, D the quotient of d by dm, where d is the mean energy imparted by ionizing radiation to the matter of massdm (see ICRU Report33) The special name of the unit for abso
36、rbed dose is the gray (Gy): 1 Gy = 1 Jkg 1 DISCUSSION Formerly, the special unit for absorbed dose was the rad: 1 rad = 10 2Jkg 1= 10 2Gy 3.1.2 calibration facility combination of an ionizing radiation source and its associated instrumentation that provides traceable, uniform, and reproducible absor
37、bed dose rates at specific locations and in a specific material. It may be used to calibrate the response of routine or other types of dosimeters as a function of absorbed dose 3.1.3 electropotential difference in potential, %E, between irradiated and unirradiated solutions in an electrochemical cel
38、l measured in millivolts 3.1.4 measurement quality assurance plan a documented program for the measurement process that quantifies the total uncertainty of the measurements (both random and systematic error components). This plan shall demonstrate traceability to national standards, and shall show t
39、hat the total uncertainty meets the requirements of the specific application 3.1.5 molar linear absorption coefficient, & quotient given by the relation from Beers law as follows: where: Units: m 2 mol 1 DISCUSSION This quantity is often referred to in the literature as molar extinction coefficient.
40、 8) Available from International Commission on Radiation Units and Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814. A = absorbance at a specified wavelength, M = molar concentration of the ions of interest (that is, ceric or cerous), and d = optical path length within the solution me
41、asured by the spectrophotometer.BSISO15555:1998 BSI 04-2000 3 3.1.6 net absorbance, %A the difference between the optical absorbance of an unirradiated dosimetric solution, A o , and the optical absorbance of an irradiated dosimetric solution, A i : %A = A o A i 3.1.7 radiation chemical yield, G(x)
42、quotient of n(x) by where: Unit: molj 1 DISCUSSION This quantity is often referred to asG value. The former special unit was (100 eV) 1 . 3.1.8 reference standard dosimetry system combination of a dosimeter and appropriate analytical instrumentation of high-metrological quality that is traceable to
43、national standards 3.1.9 traceability the ability to show that a measurement is consistent with appropriate national standards through an unbroken chain of comparisons 3.2 For other relevant terms, see Terminology E170. 4 Significance and Use 4.1 The ceric-cerous system provides a reliable means for
44、 measuring absorbed dose in water. It isbased on a process of reduction of ceric ions to cerous ions in acidic aqueous solution by ionizing radiation (1, 2). 4.2 The dosimeter is a solution of ceric sulfate and cerous sulfate in sulphuric acid in an appropriate container such as a flame-sealed glass
45、 ampoule. The solution indicates a level of absorbed dose by a change (decrease) in optical absorbance at a specified wavelength in the ultraviolet region, or a change (increase) in electropotential. A calibrated spectrophotometer is used to determine the change in absorbance and a potentiometer, wi
46、th a specially designed cell, is used to determine the change in potential in millivolts. 4.3 The dosimeter response has a temperature dependence during irradiation of 0.2% per degree celsius between0 and 62 C. 4.4 For calibration with photons, the ceric-cerous dosimeter shall be irradiated under co
47、nditions that approximate electron equilibrium. 4.5 The absorbed dose in other materials irradiated under equivalent conditions may be calculated from the absorbed dose measurement of a ceric-cerous dosimeter. Procedures for making such calculations are given in Practices E666 and E668 and GuideE126
48、1. 5 Interferences 5.1 The ceric-cerous dosimetric solution response is sensitive to impurities, particularly organic impurities. Even in trace quantities, impurities can cause a detectable change in the observed response(3). For high-accuracy results, organic materials shall not be used for any com
49、ponent in contact with the solution. The effect of trace impurities is minimized by the addition of cerous ions to the solution (4, 5). 5.2 Undesirable chemical changes in the dosimetric solution can occur if care is not taken during flame-sealing of the ampoules (see8.4). n(x) = mean amount of substance of a specified entity, x, produced, destroyed, or changed by the mean energy imparted, , to matter (see ICRU Reports14 and34)BSISO15555:1998 4 BSI 04-2000 6 Apparatus 6.1 Spectrophotometric Method For the analysis of the d
