1、Designation: E 2093 05Standard Guide forOptimizing, Controlling and Reporting Test MethodUncertainties from Multiple Workstations in the SameLaboratory Organization1This standard is issued under the fixed designation E 2093; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of 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 guide describes a protocol for optimizing, control-ling, a
3、nd reporting test method uncertainties from multipleworkstations in the same laboratory organization. It does notapply when different test methods, dissimilar instruments, ordifferent parts of the same laboratory organization functionindependently to validate or verify the accuracy of a specificanal
4、ytical measurement.1.2 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
5、use.2. Referenced Documents2.1 ASTM Standards:2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 350 Test Methods for ChemicalAnalysis of Carbon Steel,Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, andWrought IronE 415 Test Method for Optical Emission
6、 Vacuum Spectro-metric Analysis of Carbon and Low-Alloy SteelE 1329 Practice for Verification and Use of Control Chartsin Spectrochemical AnalysisE 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE 2027 Practice for Conducting Proficiency Tests
7、 in theChemical Analysis of Metals, Ores, and Related Materials2.2 ISO Standards:ISO 17025 General Requirements for the Competence ofCalibration and Testing Laboratories3ISO 9000 Quality Management and Quality System Ele-ments33. Terminology3.1 DefinitionsFor definitions of terms used in this guide,
8、refer to Terminology E 135.3.2 Definitions of Terms Specific to This Standard:3.2.1 data quality objectives, na model used by thelaboratory organization to specify the maximum error associ-ated with a report value, at a specified confidence level.3.2.2 laboratory organization, na business entity tha
9、tprovides similar types of measurements from more than oneworkstation located in one or more laboratories, all of whichoperate under a unified quality system.3.2.3 maximum deviation, nthe maximum error associ-ated with a report value, at a specified confidence level, for agiven concentration of a gi
10、ven element, determined by aspecific method, throughout a laboratory organization.3.2.4 workstation, na combination of people and equip-ment that executes a specific test method using a singlespecified measuring device to quantify one or more parameters,with each report value having an established e
11、stimated uncer-tainty that complies with the data quality objectives of thelaboratory organization.4. Significance and Use4.1 Many competent analytical laboratories comply withaccepted quality system requirements such as ISO 9000,QS9000,4and ISO 17025. When using standard test methods,their test res
12、ults on the same sample should agree with thosefrom other similar laboratories within the reproducibilityestimates index (R) published in the standard. Reproducibilityestimates are generated as part of the interlaboratory studies1This guide is under the jurisdiction of ASTM Committee E01 on Analytic
13、alChemistry for Metals, Ores and Related Materials and is the direct responsibility ofSubcommittee E01.22 on Laboratory Quality.Current edition approved May 1, 2005. Published July 2005. Originally approvedin 2000. Last previous edition approved in 2000 as E 2093 00.2For referenced ASTM standards, v
14、isit 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.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New Yo
15、rk, NY 10036.4Quality Systems Requirements, Chrysler Corporation, Ford Motor Company,and General Motors Corporationavailable from AIAG, 26200 Lahser Rd., Suite200, Southfield, MI 480347100.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Sta
16、tes.(ILS), of the type described in Practice E 1601, during thestandardization process. Competent laboratories participate inproficiency tests, such as those conducted in accordance withPractice E 2027, to confirm that they perform consistently overtime. In both ILS and proficiency testing protocols
17、, it isgenerally assumed that only one work station is used togenerate the data.4.2 Many laboratories have workloads, or logistical require-ments, or both, that dictate the use of multiple work stations.Some have multiple stations in the same area (central labora-tory format). Others stations are sc
18、attered throughout a facility(at-line laboratory format). Often, analysis reports do notidentify the workstation used for the testing, even if worksta-tions differ in their testing uncertainties. Problems can arise ifclients mistakenly attribute variation in report values to processrather then works
19、tation variability. These problems can beminimized if the laboratory organization sets, complies with,and reports a unified set of data quality objectives throughout.4.3 This guide describes a protocol for efficiently optimiz-ing and controlling variability in test results from differentworkstations
20、 used to perform the same test. It harmonizescalibration and control protocols, thereby providing the samelevel of measurement traceability and control to all worksta-tions. It streamlines documentation and training requirements,thereby facilitating flexibility in personnel assignments. Fi-nally, it
21、 offers an opportunity to claim traceability of profi-ciency test measurements to all included workstations, regard-less on which workstation the proficiency test sample wastested. The potential benefits of utilizing this protocol increasewith the number of workstations included in the laboratoryorg
22、anization.4.4 This guide can be used to identify and quantify benefitsderived from corrective actions relating to under-performingworkstations. It also provides means to track improved perfor-mance after improvements have been made.4.5 It is assumed that all who use this guide comply withISO 17025,
23、especially including the use of documented proce-dures, the application of statistical control of measurementprocesses, and participation in proficiency testing.4.6 The general principles of this protocol can be adapted toother types of measurements, such as mechanical testing andon-line process con
24、trol measurements, such as temperature andthickness gaging. In these areas, users may need to establishtheir own models for defining data quality objectives andproficiency testing may not be available or applicable.4.7 It is especially important that users of this guide takeresponsibility for ensuri
25、ng the accuracy of the measurementsmade by the workstations to be operated under this protocol. Inaddition to the checks mentioned in 6.2.3, laboratories areencouraged to use other techniques, including, but not limitedto, analyzing some materials by independent methods, eitherwithin the same labora
26、tory or in collaboration with otherequally competent laboratories. The risks associated withgenerating large volumes of data from carefully synchronized,but incorrectly calibrated multiple workstations are obviousand must be avoided.5. Summary5.1 Identify the test method and establish the data quali
27、tyobjectives to be met throughout the laboratory organization.5.2 Identify the workstations to be included in the protocoland harmonize their experimental procedures, calibrations, andcontrol strategies so that all performance data from all work-stations are directly statistically comparable.5.3 Tab
28、ulate performance data for each workstation andensure that each workstation complies with the laboratoryorganizations data quality objectives.5.4 Document items covered in 5.1-5.3.5.5 Establish and document a laboratory organization-wideproficiency test policy that provides traceability to all work-
29、stations.5.6 Operate each workstation independently as described inits associated documentation. If any changes are made to anyworkstation or its performance levels, document the changesand ensure compliance with the laboratory organizations dataquality objectives.6. Procedure6.1 Identify the test m
30、ethod and establish the data qualityobjectives to be met throughout the laboratory organization.6.1.1 Multi-element test methods can be handled concur-rently, provided that all elements are measured using commontechnology, and that the parameters that influence data qualityare tabulated and evaluate
31、d for each element individually. Anexample is Test Method E 415 that covers the analysis of plaincarbon and low alloy steel by atomic emission vacuumspectrometry. Workstations can be under manual or roboticcontrol, as long as the estimated uncertainties are within thespecified data quality objective
32、s.Avoid handling multi-elementtest methods concurrently that use different measurementtechnologies. Their procedures and error evaluations are toodiverse to be incorporated into one easy-to-manage package.An example of test methods that should not be combined intoone program is Test Methods E 350 be
33、cause those methodscover many different measurement technologies.6.1.2 Set the data quality objectives for the application ofthe method throughout the laboratory organization, usingcustomer requirements and available performance data. At theconclusion of this effort, the laboratory organization will
34、 knowthe maximum deviation allowed in any report value, at anyconcentration level, using the method of choice.An example ofa possible method for establishing data quality objectives isgiven in Annex A1.6.2 Identify the workstations to be included in the protocoland harmonize their experimental proce
35、dures, calibrations, andcontrol strategies so that all performance data from all work-stations are directly statistically comparable.6.2.1 For each workstation, list the personnel and equipmentthat significantly influence data quality. Each component ofeach workstation does not have to be identical,
36、 such as fromthe same manufacturer or model number; however, eachworkstation must perform the functions described in the testmethod.6.2.2 Harmonize the experimental procedures associatedwith each workstation to ensure that all stations are capable ofE2093052generating statistically comparable data t
37、hat can be expected tofall within the maximum allowable limits for the laboratoryorganization. Ideally, all workstations within the laboratoryorganization will have essentially the same experimental pro-cedures.6.2.3 Harmonize calibration protocols so that the samecalibrants are used to cover the sa
38、me calibration ranges for thesame elements on all instruments. Avoid the use of differentcalibrants on different instruments that may lead to calibrationbiases and uncertainties that are larger than necessary. Ensurethat all interferences and matrix effects are addressed. Verifythe calibrations with
39、 certified reference materials not used inthe calibration, when possible. Record the findings for eachworkstation.6.2.4 Use the same SPC materials and data collectionpractices on all work stations (see Note 1). Carry SPCmaterials through all procedural steps that contribute to themeasurement uncerta
40、inty. Develop control charts in accor-dance with Practice E 1329, or equivalent practice.NOTE 1Generally, it is recommended that SPC concentrations be setabout13 from the top and13 from the bottom of each calibration range. Itis also recommended that single point, moving range charts be used so that
41、calculated standard deviations reflect the normal variation in report values.6.2.5 Collect at least 20 SPC data points from each workstation to ensure that the workstations are under control andthat the control limits are representative.6.3 Tabulate performance data for each workstation andensure th
42、at each workstation complies with the laboratoryorganizations data quality objectives.6.3.1 Tabulate the SPC data by parameter (element), Refer-ence material, assumed true concentration, workstation, aver-age, upper control limit, lower control limit, and standarddeviation, as illustrated in Table 1
43、 (see Notes 2 and 3).TABLE 1 Sample SPC Control Parameter TabulationERMAssumedTrue Conc. WS Av. UCL LCL Std. Dev.C 638 0.06014 1 0.05996 0.06764 0.05228 0.002562 0.06040 0.06364 0.05716 0.001083 0.06005 0.06308 0.05702 0.00101648 0.25665 1 0.25212 0.27069 0.23355 0.006192 0.25923 0.27402 0.24444 0.0
44、04933 0.25861 0.27283 0.24439 0.00474Mn 638 0.29832 1 0.29620 0.30304 0.28936 0.002282 0.29967 0.30567 0.29367 0.002003 0.29908 0.30643 0.29173 0.00245648 0.90328 1 0.90408 0.92088 0.88728 0.005642 0.90408 0.92385 0.88431 0.006593 0.90168 0.92664 0.87672 0.00832P 638 0.00563 1 0.00543 0.00600 0.0048
45、6 0.000192 0.00575 0.00605 0.00545 0.000103 0.00571 0.00601 0.00541 0.00010648 0.03431 1 0.03413 0.03674 0.03152 0.000872 0.03447 0.03702 0.03192 0.000853 0.03434 0.03689 0.03179 0.00085S 638 0.01820 1 0.01702 0.02146 0.01258 0.001482 0.01868 0.02153 0.01583 0.00095TABLE 1 ContinuedERMAssumedTrue Co
46、nc. WS Av. UCL LCL Std. Dev.3 0.01891 0.02128 0.01654 0.00079648 0.02424 1 0.02330 0.02771 0.01889 0.001472 0.02475 0.02940 0.02010 0.001553 0.02467 0.02884 0.02050 0.00139Si 638 0.01688 1 0.01565 0.01718 0.01412 0.000512 0.01755 0.01863 0.01647 0.000363 0.01743 0.01830 0.01656 0.00029648 0.23283 1
47、0.22900 0.23911 0.21889 0.003372 0.23240 0.24404 0.22076 0.003883 0.23710 0.24619 0.22801 0.00303Cu 638 0.26588 1 0.26685 0.27555 0.25815 0.002902 0.26569 0.27295 0.25843 0.002423 0.26511 0.27276 0.25746 0.00255648 0.10700 1 0.10654 0.11089 0.10219 0.001452 0.10753 0.11086 0.10420 0.001113 0.10694 0
48、.13784 0.07604 0.01030Ni 638 0.69005 1 0.70014 0.72516 0.67512 0.008342 0.68252 0.69440 0.67064 0.003963 0.68750 0.71309 0.66191 0.00853648 0.25063 1 0.25174 0.25906 0.24442 0.002442 0.24891 0.25350 0.24432 0.001533 0.25123 0.25927 0.24319 0.00268Cr 638 0.03746 1 0.03760 0.03886 0.03634 0.000422 0.0
49、3745 0.03832 0.03658 0.000293 0.03732 0.03813 0.03651 0.00027648 0.23728 1 0.23190 0.23637 0.22743 0.001492 0.24012 0.24414 0.23610 0.001343 0.23982 0.24300 0.23664 0.00106Sn 638 0.00278 1 0.00255 0.00507 0.00003 0.000842 0.00257 0.00296 0.00218 0.000133 0.00322 0.00490 0.00154 0.00056648 0.01424 1 0.01402 0.01600 0.01204 0.000662 0.01412 0.01502 0.01322 0.000303 0.01458 0.01668 0.01248 0.00070Mo 638 0.06346 1 0.06253 0.06604 0.05902 0.001172 0.06398 0.06533 0.06263 0.000453 0.06387 0.06621 0.06153 0.00078648 0.08652 1 0.08539 0.08995 0.08083 0.001522 0.08722 0.08941 0.0
