1、Designation: E1323 15 An American National StandardStandard Guide forEvaluating Laboratory Measurement Practices and theStatistical Analysis of the Resulting Data1This standard is issued under the fixed designation E1323; the number immediately following the designation indicates the year oforiginal
2、 adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers key elements of an evaluation of alaboratorys mea
3、surement practices and the statistical analysisof the resulting data. This guide addresses an evaluation thatcovers a broad range of in-house quality measurements, someof which may be directly related to accreditation requirements.1.2 This guide provides an overview of the documentationneeded for ve
4、rification and monitoring of the practices used inthe laboratory for measurement. In addition, it guides the userin verifying that the extent of documentation and the quality ofstatistical evaluations performed on the data being generated issufficient. The user is advised to fully document all workc
5、overed by the scope of this guide as a general principle oflaboratory practice and for audit purposes, whether internal orexternal.1.3 This guide is not designed to be exhaustive for allaspects of work realized under its scope. The user is encour-aged to thoroughly realize (achieve in practice) the
6、principlesset forth in this guide, consulting other relevant standards andindustry documents when appropriate.2. Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE178 Practice for Dealing With Outlying ObservationsE456 Terminology Relat
7、ing to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1169 Practice for Conducting Ruggedness TestsE2554 Practice for Estimating and Monitoring the Uncer-tainty of Test Results of a Test Method Using ControlChart TechniquesE2587
8、 Practice for Use of Control Charts in StatisticalProcess ControlE2655 Guide for Reporting Uncertainty of Test Results andUse of the Term Measurement Uncertainty in ASTM TestMethods3. Terminology3.1 Terms are defined in Terminology E456.4. Significance and Use4.1 This guide is intended to provide gu
9、idance for labora-tory quality managers, accrediting bodies and assessors inevaluating the measurement practices of a laboratory, theprotocol for statistically analyzing the resulting data from thesepractices, and the statistical results from these practices.4.2 This guide is generic in the sense th
10、at it covers the entirerange of in-house quality measurement practices found in atesting laboratory, and the results of the described evaluationmay be used by accrediting agencies for assessment purposesto determine whether their requirements can be satisfiedthrough the laboratorys existing quality
11、data program.4.3 It is not the intent of this guide to serve as sole criterionfor evaluating and accrediting laboratories. Evaluation ofmeasurement practices is only one aspect in a comprehensivequality program.5. Purpose of Evaluating Measurement Practices and theStatistical Analysis of the Resulti
12、ng Data5.1 Data generated from the measurement practices of alaboratory are evaluated to determine its bias and precisionperformance, and to determine if the laboratory correctly andefficiently analyzes and reacts to its own data.6. Documentation of Measurement Practices and theStatistical Protocol
13、for Analyzing the Resulting Data6.1 Documentation Relative to Calibration:6.1.1 The material to be measured should be documentedtogether with its source, expiration or shelf-life date, theaccuracy, and any preparations or conditions required whichare specific to this material before it can be utiliz
14、ed as acalibration material. Any additional components, reagents, or1This guide is under the jurisdiction of ASTM Committee E11 on Quality andStatistics and is the direct responsibility of Subcommittee E11.20 on Test MethodEvaluation and Quality Control.Current edition approved April 1, 2015. Publis
15、hed May 2015. Originallyapproved in 1989. Last previous edition approved in 2009 as E1323 09. DOI:10.1520/E1323-15.2For 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 t
16、he standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1physical sources used along with this material, which couldpotentially alter the reliability of the material, should also bedocument
17、ed.6.1.2 The identification of the equipment used, togetherwith the date and operator responsible for the run, and anypreparations involved with the calibration run should bedocumented.6.1.3 The type of data representation to be used, includingthe exact number of data points to be used in the comput
18、ationof an average, standard deviation, or range, as well as how andwhen these data points are to be generated should be docu-mented. This requires information regarding testing ofreplicates, duplicates, or single runs tested on one day, a seriesof days, or a specific time interval to be clearly sta
19、ted for eachset of data.6.1.4 The mathematical formula for obtaining control limits,the frequency of computing new limits together with rules ofacceptability of the new limits, should be documented when-ever control limits are applied to a chart.6.1.5 The corrective action taken whenever data points
20、indicate that an out of control condition exists, or whenevertrend analysis indicates a change or shift in the instrumentresponse should be recorded.6.1.6 A table of actual measured values for each calibrationor calibration check, the corresponding reference value, and thecorresponding date should b
21、e documented.6.2 Documentation Relative to Method Precision:6.2.1 The precision of each test method used in the labora-tory should be determined using Practice E691 or otherequivalent standards.6.2.2 The reference of the specific method being followedfor each set of data, as well as any changes to t
22、he methodshould be documented. If a method has not been published,then the laboratory should prepare a detailed procedure.6.2.3 The type of run (duplicate, replicate, single) used togenerate the data points, including specific directions on howto prepare and test a duplicate or replicate specimen, s
23、hould bedocumented.6.2.4 The time interval for testing, or a date for each datapoint if a time interval is not practical, should be documented.6.2.5 Directions on how to statistically compare the labora-tory results of precision with a known statement of precisionfor that method should be documented
24、. These directions shouldinclude the specific statistical test, the number of data pointsused for the test and the acceptable level of precision, be itknown either from other studies on this specific method or asa limit determined by the laboratory itself.6.2.6 The method for determining if outliers
25、 exist should beaccording to Practice E178 or other equivalent standards.6.2.6.1 The method should be documented, stating when itis acceptable to ignore such data points when computingcontrol limits.6.2.6.2 Outliers, which were not used in the computation ofcontrol limits, should be documented.6.2.7
26、 The precision of each test method used in the labora-tory should be documented.6.2.8 The precision of a test method should be documentedin the test report for that method.6.3 Documentation Relative to Instrument or Method Bias:6.3.1 The method for determining if bias exists and thefrequency for con
27、tinued checks on the instrument or methodhaving a bias should be documented, including any adjust-ments made to the test data as a result of the bias determinedfrom these measurements (see Practice E177).6.3.2 A table of actual values and the corresponding datesshould be documented for each instrume
28、nt and method used inthe laboratory.6.3.3 The bias of an instrument or method should bedocumented in the test report for that instrument or method.6.4 Documentation Relative to Operator Precision andBias:6.4.1 The material, methods, and equipment used to deter-mine levels of operator precision and b
29、ias should be docu-mented.6.4.2 The source of stated bias of the material, the currentprecision and bias of the equipment, and the current precisionand bias of the method should be documented, together withthe exact computations used to determine the single or groupoperator precision, bias, or both.
30、6.4.3 The number of data points generated per operator forthis comparison test as well as the protocol design should bedocumented.6.4.4 The limits of acceptability for both operator bias andoperator precision should be documented.6.4.5 The records should show the frequency of obtainingoperator bias
31、and operator precision as well as the correctiveaction taken whenever an operator fails to meet the limits ofacceptability.6.4.6 A table of actual measured values, the correspondingreference values, and corresponding dates for each operatorshould be documented.6.5 Documentation Relative to Uncertain
32、ty:6.5.1 The uncertainty of results for each test method used inthe laboratory should be determined according to PracticesE2554 or E2655 or other equivalent standards.6.5.2 The actual measured values and the correspondingdate used in the calculation of uncertainty should be docu-mented.6.5.3 The unc
33、ertainty of each test method used in thelaboratory should be documented.6.5.4 The uncertainty of a test method should be docu-mented in the test report for that method.6.6 Documentation Relative to Ruggedness:6.6.1 The ruggedness of each test method used in thelaboratory should be determined accordi
34、ng to Guide E1169 orother equivalent standards.6.6.2 The factors used in the ruggedness study, theirmagnitude, statistical significance and date of the study shouldbe documented.6.6.3 The experimental design, factor settings and actualmeasured values for each experimental run should be docu-mented.6
35、.6.4 The statistically significant ruggedness factors shouldbe documented for each test method used in the laboratory.E1323 1526.6.5 The factor settings for each statistically significantfactor in a method should be documented in the test report forthat method.7. Evaluation of the Laboratorys Measur
36、ement Practicesand of the Statistical Analysis from the Resulting Data7.1 1 A general overview of the laboratorys documentationof measurement practices and the statistical analysis of the datashould be made, verifying that all practices cited are actually inuse and the rules stated by the laboratory
37、 for the generation anduse of the data are followed.7.2 A walk-through of the laboratory to verify the locationof all data representation charts should be made. Discussionswith laboratory personnel to verify their knowledge of themeasurement practices also should be made.7.3 The choice of representa
38、tion of the data, as well as thegeneration of control chart limits, should be reviewed todetermine if appropriate models have been used for each typeof population. For further information, see Practice E2587.7.4 Each piece of equipment used in the laboratory togenerate a test result should be calibr
39、ated on a periodic basis.The raw data from the calibration records should be comparedto the status indicated for that piece of equipment. Every rawdata point outside of control limits or outside of specificationlimits should have a corresponding documented correctiveaction which resulted in restorin
40、g the equipment to normaloperation (status of in calibration) or resulted in a recommen-dation for further work (status of out of calibration). Dates andresults from the raw data should agree with the status shown onthat piece of equipment.7.5 All charts should be viewed for trend analysis. Checksof
41、 trends or shifts should be documented, including theinterpretation of those found to be beyond acceptance limits bylaboratory personnel as well as the corrective action taken. Thisinformation does not have to be on the chart itself, but it shouldbe documented somewhere by the laboratory and availab
42、le forreview upon request by the assessor.7.6 All data calculations for any kind of limits, be it foraccuracy or precision of equipment, precision or bias ofmethods, or bias or precision of an operator, should bereviewed to determine if the appropriate type of chart has beenused and the optimum numb
43、er of data points have been used.7.7 Spot checks of the raw data should also be made toverify that no data point is being disregarded unless an outliertest has indicated that the data point can be omitted from thecalculation of control limits. The outlier is still documented asa check and listed in
44、the table of data with corresponding dates.7.8 Raw data checks should also be made to verify thefrequency of testing for calibration. For example, a measure-ment practice that requires a replicate be tested on 1 of every10 specimens received, should show, through raw data, that theappropriate number
45、 of replicate tests were performed, reported,and transferred to the corresponding chart.8. Use of the Evaluation by Accrediting Bodies8.1 An accrediting body may use the evaluation to deter-mine the methods of monitoring the quality control of thelaboratory, such as the extent and frequency of futur
46、e on-sitevisits to the laboratory,review of the data from the measure-ment practices, and review of the data from proficiency testingprograms to verify the laboratorys continued state of statisticalcontrol.9. Keywords9.1 accreditation; laboratory accreditation; laboratory mea-surement practices; sta
47、tistical analysisASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of
48、 such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for a
49、dditional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by con
