ASTM_D_6689_-_01_2011.pdf

Designation:D668901(Reapproved 2011)Standard Guide forOptimizing,Controlling and Reporting Test MethodUncertainties from Multiple Workstations in the SameLaboratory Organization1This standard is issued under the fixed designation D6689;the number immediately following the designation 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 optimizing,controlling,and reporting test method uncertainties from mul-tiple workstations in the same laboratory organization.It doesnot apply when different test methods,dissimilar instruments,or different parts of the same laboratory organization functionindependently to validate or verify the accuracy of a specificanalytical 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 requirements prior to use.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD6091 Practice for 99%/95%Interlaboratory DetectionEstimate(IDE)for Analytical Methods with NegligibleCalibration ErrorD6512 Practice for Interlaboratory Quantitation EstimateE135E415 Test Method for Analysis of Carbon and Low-AlloySteel by Spark Atomic Emission SpectrometryE1763 Guide for Interpretation and Use of Results fromInterlaboratory Testing of Chemical Analysis MethodsSTP 15D ASTM Manual on Presentation of Data andControl Chart Analysis,Prepared by Committee E11 onStatistical Methods2.2 Other Documents:ISO 17025(previously ISO Guide 25)General Require-ments for the Competence of Calibration and TestingLaboratories33.Terminology3.1 DefinitionsFor definitions of terms used in this Guide,refer to Terminology E135 and D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 laboratory organizationa business entity that pro-vides similar types of measurements from more than oneworkstation located in one or more laboratories,all of whichoperate under the same quality system.NOTE1Key aspects of a quality system are covered in ISO 17025 andinclude documenting procedures,application of statistical control tomeasurement processes and participation in proficiency testing.3.2.2 maximum deviationthe maximum error associatedwith a report value,at a specified confidence level,for a givenconcentration of a given element,determined by a specificmethod,throughout a laboratory organization.3.2.3 measurement quality objectivesa model used by thelaboratory organization to specify the maximum error associ-ated with a report value,at a specified confidence level.3.2.4 workstationa combination of people and equipmentthat executes a specific test method using a single specifiedmeasuring device to quantify one or more parameters,witheach report value having an established estimated uncertaintythat complies with the measurement quality objectives of thelaboratory organization.4.Significance and Use4.1 Many analytical laboratories comply with acceptedquality system requirements such as NELAC chapter 5(seeNote 2)and ISO 17025.When using standard test methods,their test results on the same sample should agree with thosefrom other similar laboratories within the reproducibilityestimates(R2)published in the standard.Reproducibility1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.02 on Quality Systems,Specification,and Statistics.Current edition approved May 1,2011.Published June 2011.Originallyapproved in 2001.Last previous edition approved in 2006 as D6689 01(2006).DOI:10.1520/D6689-01R11.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 estimates are generated during the standardization process aspart of the interlaboratory studies(ILS).Many laboratoriesparticipate in proficiency tests to confirm that they performconsistently over time.In both ILS and proficiency testingprotocols,it is generally assumed that only one workstation isused to generate the data(see 6.5.1).NOTE2NELAC chapter 5 allows the use of a Work Cell wheremultiple instruments/operators are treated as one unit:the performance ofthe Work Cell is tracked rather than each workstation independently.Thisguide is intended to go beyond the Work Cell to achieve the benefits ofmonitoring workstations independently.4.2 Many laborator