ASTM_D_7808_-_22.pdf

Designation:D780822Standard Practice forDetermining the Site Precision of a Process StreamAnalyzer on Process Stream Material1This standard is issued under the fixed designation D7808;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.INTRODUCTIONWhen a process stream analyzer is used to monitor or control a process,the results produced by theanalyzer are typically used as surrogates for values that would otherwise have been obtained viaanalyses of process samples using a Primary Test Method(PTM).Successful application of theanalyzer requires that the Predicted Primary Test Method Result(PPTMR)produced by the analyzeragrees with the Primary Test Method Result(PTMR)to within some user specified accuracy(bias andprecision).To achieve this goal,it is typically necessary to develop a correlation that relates raw,Uncorrected Analyzer Results(UARs)to PTMRs.The correlation and the analyzers performance arethen assessed during the analyzer validation to establish the expected agreement between the PPTMRand PTMR.In establishing the correlation,and assessing the performance,it is necessary to know theprecision of both the PPTMR and the PTMR.The precision of the PTMRs is typically establishedthrough statistical quality control procedures described in D6299.The precision of the PPTMRs isestablished via procedures described herein.The techniques used to determine process analyzer siteprecision can also be used for ongoing quality control of the analyzer measurement system.1.Scope*1.1 This practice describes a procedure to quantify the siteprecision of a process analyzer via repetitive measurement of asingle process sample over an extended time period.Theprocedure may be applied to multiple process samples to obtainsite precision estimates at different property levels1.1.1 The site precision is required for use of the statisticalmethodology of D6708 in establishing the correlation betweenanalyzer results and primary test method results using PracticeD7235.1.1.2 The site precision is also required when employing thestatistical methodology of D6708 to validate a process analyzervia Practices D3764 or D6122.1.2 This practice is not applicable to in-line analyzers wherethe same quality control sample cannot be repetitively intro-duced.1.3 This practice is meant to be applied to analyzers thatmeasure physical properties or compositions.1.4 This practice can be applied to any process analyzersystem where the feed stream can be captured and stored insufficient quantity with no stratification or stability concerns.1.4.1 The captured stream sample introduction must be abletomeettheprocessanalyzersampleconditioningrequirements,feed temperature and inlet pressure.1.4.2 This practice is designed for use with samples that aresingle liquid phase,petroleum products whose vapor pressure,at sampling and sample storage conditions,is less than or equalto 110 kPa(16.0 psi)absolute and whose D86 final boilingpoint is less than or equal to 400 C(752 F).NOTE1The general procedures described in this practice may beapplicable to materials outside this range,including multiphase materials,but such application may involve special sampling and safety consider-ations which are outside the scope of this practice.1.5 The values for operating conditions are stated in SI unitsand are to be regarded as the standard.The values given inparentheses are the historical inch-pound units for informationonly.1.6 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.25 on Performance Assessment and Validation of ProcessStream Analyzer Systems.Current edition approved April 1,2022.Published June 2022.Originallyapproved in 2012.Last previous edition approved in 2018 as D7808 18.DOI:10.1520/D7808-22.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trad