1、Designation:E209305 Designation: E2093 12Standard Guide forOptimizing, Controlling and ReportingAssessing TestMethod Uncertainties from Multiple Workstations in theSame Laboratory Organization1This standard is issued under the fixed designation E2093; the number immediately following the designation
2、 indicates the year oforiginal 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 describes a protocol for o
3、ptimizing, controlling, and reporting test method uncertainties from multipleworkstations in the same laboratory organization. It does not apply when different test methods, dissimilar instruments, or differentparts of the same laboratory organization function independently to validate or verify the
4、 accuracy of a specific analyticalmeasurement.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regula
5、torylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related MaterialsE350 Test Methods for Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and WroughtIronE415 Test Me
6、thod for Atomic Emission Vacuum Spectrometric Analysis of Carbon and Low-Alloy SteelE1329 Practice for Verification and Use of Control Charts in Spectrochemical AnalysisE1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical MethodE2027 Practice for Conduc
7、ting Proficiency Tests in the Chemical Analysis of Metals, Ores, and Related Materials2.2 ISO Standards:3ISO 17025ISO/IEC 17025 General Requirements for the Competence of Calibration and Testing Laboratories ISO 9000QualityManagement and Quality System Elements3ISO 9000 Quality Management and Qualit
8、y System Elements2.3 Other Standards:Measurement Systems Analysis Reference Manual43. Terminology3.1 DefinitionsFor definitions of terms used in this guide, refer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 data quality objectives, na model used by the laboratory org
9、anization to specify the maximum error associated with areport value, at a specified confidence level.3.2.2laboratory organization, na business entity that provides similar types of measurements from more than one workstationlocated in one or more laboratories, all of which operate under a unified q
10、uality system.1This guide is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.22 on Laboratory Quality.Current edition approved MayJune 1, 2005.2012. Published July 2005.2012. Originally a
11、pproved in 2000. Last previous edition approved in 20002005 as E2093 005.DOI: 10.1520/E2093-05.10.1520/E2093-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the
12、 standards Document Summary page on the ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.3Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, www.ansi.org or from Internati
13、onal Organization forStandardization (ISO) at www.iso.ch.4Quality Systems Requirements, Chrysler Corporation, Ford Motor Company, and General Motors Corporationavailable from AIAG, 26200 Lahser Rd., Suite 200,Southfield, MI 480347100.4Measurement Systems Analysis Reference Manual, Copyright 1990, 19
14、95, Chrysler Corporation, Ford Motor Company, and General Motors Corporation, available fromAIAG, 26200 Lahser Rd., Suite 200, Southfield, MI 480347100, www.aiag.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have
15、 been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official docu
16、ment.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.3maximum deviation, nthe maximum error associated with a report value, at a specified confidence level, for a givenconcentration of a given element, determined by a specific met
17、hod, throughout a laboratory organization.3.2.4workstation, na combination of people and equipment that executes a specific test method using a single specifiedmeasuring device to quantify one or more parameters, with each report value having an established estimated uncertainty thatcomplies with th
18、e data quality objectives of the laboratory organization.4. Significance and Use4.1 Many competent analytical laboratories comply with accepted quality system requirements such as ISO 9000, QS9000, andISO 17025.requirements. When using standard test methods, their test results on the same sample sho
19、uld agree with those fromother similar laboratories within the reproducibility estimates index (R) published in the standard. Reproducibility estimates aregenerated as part of the interlaboratory studies (ILS), of the type described in Practice E1601, during the standardization processCompetent labo
20、ratories participate in proficiency tests, such as those conducted in accordance with Practice E2027, to confirm thatthey perform consistently over time. In both ILS and proficiency testing protocols, it is generally assumed that only one workstation is used to generate the data.4.2 Many laboratorie
21、s have workloads, or logistical requirements, or both, that dictate the use of multiple work stations. Somehave multiple stations in the same area (central laboratory format). OthersOther stations are scattered throughout a facility (at-linelaboratory format) and in some cases may even reside at dif
22、ferent facilities. Often, analysis reports do not identify the workstationused for the testing, even if workstations differ in their testing uncertainties. Problems can arise if clients mistakenly attributevariation in report values to process rather thenthan workstation variability. These problems
23、can be minimized if the laboratoryorganization sets, complies with, and reports a unified set determines the overall uncertainty associated with results reported frommultiple workstations and assesses the significance of data quality objectives throughout. the analytical uncertainty to theproduction
24、 process.4.3 This guide describes a protocol for efficiently optimizing and controlling variability in test results from differentworkstations used to perform the same test. It harmonizes calibration and control protocols, thereby providing the same level ofmeasurement traceability and control to al
25、l workstations. It streamlines documentation and training requirements, therebyfacilitating flexibility in personnel assignments. Finally, it offers an opportunity to claim traceability of proficiency testmeasurements to all included workstations, regardless on which workstation the proficiency test
26、 sample was tested. The potentialbenefits of utilizing this protocol increase with the number of workstations included in the laboratory organization.4.4 This guide can be used to identify and quantify benefits derived from corrective actions relating to under-performingworkstations. It also provide
27、s means to track improved performance after improvements have been made.4.5 It is assumed that all who use this guide comply with ISO 17025, especially including will have an established laboratoryquality system. This system shall include the use of documented procedures, the application of statisti
28、cal control of measurementprocesses, and participation in proficiency testing. ISO/IEC 17025 describes an excellent model for establishing this type oflaboratory quality system.4.6 The general principles of this protocol can be adapted to other types of measurements, such as mechanical testing andon
29、-line process control measurements, such as temperature and thickness gauging. In these areas, users may need to establish theirown models for defining data quality objectives and proficiency testing may not be available or applicable.4.7 It is especially important that users of this guide take resp
30、onsibility for ensuring the accuracy of the measurements madeby the workstations to be operated under this protocol. In addition to the checks mentioned in 6.2.3, laboratories are encouragedto use other techniques, including, but not limited to, analyzing some materials by independent methods, eithe
31、r within the samelaboratory or in collaboration with other equally competent laboratories. The risks associated with generating large volumes of datafrom carefully synchronized, but incorrectly calibrated multiple workstations are obvious and must be avoided.4.8 This guide is not intended to provide
32、 specific guidance on development of statements of measurement uncertainty such asthose required by ISO/IEC 17025. However, the statistical calculations generated using this guide may provide a useful estimateof one Type A uncertainty component used in the calculation of an expanded uncertainty.4.9
33、This guide does not provide any guidance for determining the bias related to the use of multiple workstations in a laboratoryorganization.5. Summary5.1 Identify the test method and establish the data quality objectives to be met throughout the laboratory organization.5.2 Identify the workstations to
34、 be included in the protocol and harmonize their experimental procedures, calibrations, andcontrol strategies so that all performance data from all workstations are directly statistically comparable.5.3 Tabulate performance data for each workstation and ensure that each workstation complies with the
35、 laboratoryorganizations data quality objectives.5.4Document items covered in 5.1-5.35.4 Perform statistical analysis of the data from the workstations to quantify variation within each workstation and assessacceptability of the variation of the pooled workstation data.5.5 Document items covered in
36、5.1 5.4.5.56 Establish and document a laboratory organization-wide proficiency test policy that provides traceability to all workstations.E2093 1225.67 Operate each workstation independently as described in its associated documentation. If any changes are made to anyworkstation or its performance le
37、vels, document the changes and ensure compliance with the laboratory organizations data qualityobjectives.6. Procedure6.1Identify the test method and establish the data quality objectives to be met throughout the laboratory organization.6.1 Test Method Identification and Establishment of the Data Qu
38、ality Objectives:6.1.1 Multi-element test methods can be handled concurrently, provided that all elements are measured using commontechnology, and that the parameters that influence data quality are tabulated and evaluated for each element individually. Anexample is Test Method E415 that covers the
39、analysis of plain carbon and low alloy steel by atomic emission vacuum spectrometry.Workstations can be under manual or robotic control, as long as the estimated uncertainties are within the specified data qualityobjectives. Avoid handling multi-element test methods concurrently that use different m
40、easurement technologies. Their proceduresand error evaluations are too diverse to be incorporated into one easy-to-manage package. An example of test methods that shouldnot be combined into one program is Test Methods E350 because those methods cover many different measurement technologies.6.1.2Set
41、the data quality objectives for the application of the method throughout the laboratory organization, using customerrequirements and available performance data. At the conclusion of this effort, the laboratory organization will know the maximumdeviation allowed in any report value, at any concentrat
42、ion level, using the method of choice. An example of a possible methodfor establishing data quality objectives is given in Annex A1.6.1.2 Set the data quality objectives for the application of the method throughout the laboratory organization, using customerrequirements and other available data. Pos
43、sible sources of other data may include production process data demonstrating the needfor and values of specific analytical process control limits. At the conclusion of this effort, the laboratory organization will knowthe population standard deviation at specific concentrations. The laboratory can
44、then use these data to draw conclusions about theacceptability of the data produced by the population of work stations.6.2 Identify the workstations to be included in the protocol and harmonize their experimental procedures, calibrations, andcontrol strategies so that all performance data from all w
45、orkstations are directly statistically comparable.6.2.1 For each workstation, list the personnel and equipment that significantly influence data quality. Each component of eachworkstation does not have to be identical, such as from the same manufacturer or model number; however, each workstation mus
46、tperform the functions described in the test method.6.2.2 Harmonize the experimental procedures associated with each workstation to ensure that all stations are capable ofgenerating statistically comparable data that can be expected to fall within the maximum allowable limits for the laboratoryorgan
47、ization. Ideally, all workstations within the laboratory organization will have essentially the same experimental procedures.6.2.3 Harmonize calibration protocols so that the same calibrants are used to cover the same calibration ranges for the sameelements on all instruments. Avoid the use of diffe
48、rent calibrants on different instruments that may lead to calibration biases anduncertainties that are larger than necessary. Ensure that all interferences and matrix effects are addressed. Verify the calibrationswith certified reference materials not used in It is reasonable to expect that similarl
49、y configured instruments will yield similarinterference and matrix effect correction factors. Validate the calibration, when possible.analytical method for each workstation.Record the findings for each workstation.6.2.4 Use the same SPC materials and data collection practices on all work stations (see Note 1). Carry SPC materials throughall procedural steps that contribute to the measurement uncertainty. Develop control charts in accordance with Practice E1329, orequivalent practice.NOTE 1Generally, it is recommended that SPC concentrations be set about13 from the to
