1、Designation: D 7282 06Standard Practice forSet-up, Calibration, and Quality Control of Instruments Usedfor Radioactivity Measurements1This standard is issued under the fixed designation D 7282; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers consensus criteria for the calibra-tion and quality control of nuclear in
3、struments. This practice isprovided for establishing appropriate quality control param-eters at instrument startup, calibration of nuclear countinginstruments and the continuing monitoring of quality controlparameters. Calibrations are usually performed to establish theoperating parameters of the in
4、strument. This practice addressesthe typically used nuclear counting instruments: alpha spec-trometer, gamma spectrometer, gas proportional counter andliquid scintillation counter.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstand
5、ard.1.3 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.2. Referenc
6、ed Documents2.1 ASTM Standards:2D 1129 Terminology Relating to WaterD 3648 Practices for the Measurement of RadioactivityD 4375 Practice for Basic Statistics in Committee D19 onWater2.2 Other Standards:ISO/IEC 17025 General Requirements for the Competenceof Testing and Calibration Laboratories3ISO 1
7、995 Guide to the Expression of Uncertainty in Mea-surement3ANSI N42.22 Traceability of Radioactive Sources to theNational Institute of Standards and Technology (NIST)and Associated Instrument Quality Control4ANSI N42.23 Measurement andAssociated InstrumentationQuality Assurance for Radioassay Labora
8、tories4ANSI/HPS N13.30 Performance Criteria for Radiobioas-say43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 acceptable verification ratio (AVR)ratio of the dif-ference between measured value of the verification sample andthe known value added to the verification sample to t
9、he squareroot of the sum of the squares of their associated combinedstandard uncertainties. See Eq 8 in 16.2.13.3.1.2 background subtraction count (BSC)a source countused to determine the background to be subtracted from thesample test source count.3.1.3 calibrationdetermining the instrument respons
10、e to aknown amount of radioactive material.3.1.4 calibration source (CS)a known quantity of radio-active material, traceable to a national standards body, preparedfor the purpose of calibrating nuclear instruments.3.1.5 continuing instrument quality controlmeasurementstaken to ensure that an instrum
11、ent responds in the same mannersubsequent to its calibration.3.1.6 instrument check source (ICS)a radioactive source,not necessarily traceable to a national standards body, that isused to confirm the continuing satisfactory operation of aninstrument.3.1.7 instrument contamination check (ICC)a measur
12、e-ment to determine if a detector is contaminated with radioac-tivity.3.1.8 instrument quality control charta chart developed toevaluate the response of an instrument to predetermined,statistically based limits.3.1.9 instrument quality tolerance limita limit establishedto evaluate the acceptable res
13、ponse of an instrument.3.1.10 known value (KV)known value of the analyteactivity added to the verification sample. See Eq 6 in 16.2.11.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.04 on Methods of RadiochemicalAnalysis.Cu
14、rrent edition approved Dec. 15, 2006. Published January 2007.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.
15、3Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM Inte
16、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.11 mean and standard deviationsee Practice D 4375.3.1.12 measured value (MV)measured value of the veri-fication sample. See Eq 4 in 16.2.9.3.1.13 measurement quality objective (MQO)quantitativeor quali
17、tative statement of a performance objective or require-ment for a particular method performance characteristic (1).53.1.14 national standards bodyan organization such asNational Institute of Standards and Technology (NIST) oranother national standards body that provides standards trace-able to BIPM
18、(Bureau International des Poids et Mesures(International Bureau of Weights and Measures). Traceabilityis accomplished with guidance from ANSI N42.22.3.1.15 quality manual (QM)a document stating the man-agement policies, objectives, principles, organizational struc-ture and authorities, accountabilit
19、y, and implementation of alaboratorys quality system, to assure the quality of its data.3.1.15.1 DiscussionThe quality manual shall documentthe process by which appropriate analytical methods areselected, their capability is evaluated and their performance isdocumented. The analytical methods manual
20、 and standardoperating procedure manuals shall be part of but not necessar-ily included in the quality manual. The quality manual orstandard operating procedures, or both, shall also includeinstructions that prescribe corrective action, for example, in theevent of instrument check source (ICS), or i
21、nstrument contami-nation check (ICC), or background subtraction count (BSC), ora combination thereof, failure.3.1.16 relative standard deviation (RSD)relative standarddeviation of the mean expressed as a percentage (also known ascoefficient of variation). See Practice D 4375 and 16.2.7.3.1.17 sample
22、 test source (STS)a sample, sample aliquant,or final product of a chemical or physical process prepared forthe purpose of activity determination.3.1.18 working calibration source (WCS)a calibrationsource (see 3.1.4), including those diluted or prepared bychemical procedure for the purpose of calibra
23、ting an instru-ment.3.2 For definition of other terms used in this practice refer toTerminology D 1129.4. Summary of Practice4.1 This practice summarizes information and guidance forset-up, calibration and quality control for nuclear countinginstruments. The procedure is divided into four main secti
24、ons:Introduction Sections 1 through 6Instrument set-up Sections 7 through 9Initial instrument quality control testing Sections 10 through 13Calibration Sections 14 through 19Continuing instrument quality control testing Sections 20 through 255. Significance and Use5.1 This practice is consistent wit
25、h a performance-basedapproach wherein the frequency of re-calibration and instru-ment testing is linked to a laboratorys continuing performancewith its quality control results. Under the premise of thispractice, a laboratory demonstrates that its instrument perfor-mance is acceptable for analyzing s
26、ample test sources.5.2 When a laboratory demonstrates acceptable perfor-mance based on continuing instrument quality control data(that is, QC charts), batch QC samples (that is, blanks,laboratory control samples, replicates, matrix spikes, and otherbatch QC samples as may be applicable) and independ
27、entreference materials, traditional schedule-driven instrumentrecalibration is permissible but unnecessary.5.3 When continuing instrument QC, batch QC, or indepen-dent reference material sample results indicate that instrumentresponse has exceeded established control or tolerance limits,instrument c
28、alibration is required. Other actions related tosample analyses on the affected instruments may be requiredby the laboratory QM.5.4 The data obtained while following this Practice willmost likely reside in computer storage. This data remains in thecomputer storage where it is readily retrievable and
29、 as neces-sary is used to produce plots, graphs, spreadsheets and othertypes of displays and reports. Frequency and performance ofdata storage backup should be specified in the laboratory QM.6. Hazards6.1 The vendor supplied safety instructions and laboratorysafety regulations should be consulted be
30、fore using electronicand electrical equipment.6.2 Corrosive, flammable, reactive and toxic materials maybe used when performing some steps in this practice. Becognizant of hazards involved with all materials and processesemployed and comply with any and all applicable health andsafety procedures, pl
31、ans and regulations. Material Safety DataSheets are a source of information.INSTRUMENT SET-UP7. Scope7.1 Instructions are provided for initial set-up of instrumentsused for activity measurements. These instructions may also beapplied when the operating parameters of an instrument arebeing reestablis
32、hed.8. Significance and Use8.1 Successful set-up of an instrument and its subsequentroutine use depend, at least in part; on how well the manufac-turers instructions are written and followed. Thus the manu-facturers recommendations are an integral part of this process.Success also depends on how wel
33、l the laboratory has planned,developed and documented its own protocol for instrument useand how well personnel are trained.9. Instrument Set-up9.1 Gas Proportional Counting Initial Instrument Set-up:9.1.1 Upon initial set-up, after major repair or service, orwhen QC results indicate the need to ree
34、stablish operatingparameters for an instrument, measure a suitable calibrationsource (that is, ICS or WCS) as specified in the laboratory QMand/or manufacturers protocol to confirm that the instrumentresponds according to QM or manufacturers specifications.The instrument set up and initial calibrati
35、on records should be5The boldface numbers in parentheses refer to the list of references at the end ofthis standard.D7282062maintained per applicable record requirements. ISO/IEC 17025includes information regarding the type of records to save.9.1.2 If the instrument being configured has previously b
36、eenused to generate sample test source results, the “as-found”instrument settings (that is, operating voltage and discriminatorsettings) should be recorded and compared to previous “as-left” parameters to ensure that instrument configuration hasbeen maintained. If the instrument configuration has ch
37、anged,an investigation into the potential impact of the changes shallbe conducted and appropriate corrective action taken.9.1.3 Establish appropriate instrument operational param-eters for the intended measurements. For example, acquirevoltage plateaus and establish the alpha or beta, or both,platea
38、u operating voltages, and alpha or beta, or both, discrimi-nator settings (that is, adjust for crosstalk). Instrument set upand configuration should be optimized for the intended appli-cations. For example, it may be desirable to perform voltageplateaus and optimize discriminator settings using a di
39、stributedsource or a specific radionuclide (for example, a 2-in.diameter230Th source as opposed to a point sourcecontaining210Po) when intended applications use a differentsource geometry or radionuclide. If instrument set-up andconfiguration deviates from the defaults recommended by themanufacturer
40、, the configuration and procedure to be used shallbe specified in detail in the laboratory QM. Operating param-eters should be established to produce consistency in detectioncharacteristics across multiple detectors used for a commonapplication. When the instrument operational parameters aresatisfac
41、torily established, record the “as-left” instrument set-tings for future reference.9.2 Gamma Spectrometry Initial Instrument Set-up:9.2.1 Upon initial set-up, after major repair or service, orwhen QC results indicate the need to reestablish operatingparameters for an instrument, measure a suitable c
42、alibrationsource (that is, ICS or WCS) as specified in the laboratory QMand/or manufacturers protocol to confirm that the instrumentresponds according to QM or manufacturer specifications (forexample, full-width at half maximum resolution, peak-to-Compton ratio and detector efficiency). The instrume
43、nt set-upand initial calibration records should be maintained per appli-cable record requirements. ISO/IEC 17025 includes informa-tion regarding the type of records to save.9.2.2 If the instrument being configured has previously beenused to generate sample test source results, the “as-found”instrume
44、nt settings (that is, detector bias, amplifier gain,analog-to- digital converter (ADC) range, or equivalent digitalspectrometer settings) should be recorded and compared toprevious “as-left” parameters to ensure that instrument con-figuration has been maintained. If the instrument configurationhas c
45、hanged, an investigation into the potential impact of thechanges shall be conducted and appropriate corrective actiontaken.9.2.3 Establish the energy range for the spectrometer toinclude all gamma emission energies of interest to the labora-tory. Adjust the amplifier gain, ADC range, or equivalentdi
46、gital spectrometer settings, to establish the desired energy perchannel relationship. When the instrument operational param-eters are satisfactorily established, record the instrument set-tings for future reference.9.3 Alpha Spectrometry Initial Instrument Set-up:9.3.1 Upon initial set-up, after maj
47、or repair or service, orwhen QC results indicate the need to reestablish operatingparameters for an instrument, measure a suitable calibrationsource (that is, ICS or WCS) as specified in the laboratory QMand/or manufacturers protocol to confirm that the instrumentresponds according to QM or manufact
48、urers specifications(for example, bias voltage setting, full-width at half maximumresolution, detector efficiency and background). The instru-ment set-up and initial calibration records should be main-tained per applicable record requirements. ISO/IEC 17025includes information regarding the type of
49、records to save.9.3.2 If the instrument being configured has previously beenused to generate sample test source results, the “as-found”instrument settings (for example, detector bias) should berecorded and compared to previous “as-left” parameters toensure that instrument configuration has been maintained. Ifthe instrument configuration has changed, an investigation intothe potential impact of the changes shall be conducted andappropriate corrective action taken.9.3.3 Establish the energy range for the spectrometer toinclude all alpha emission energies of
