ASTM_D_6621_-_00_2012.pdf

Designation:D662100(Reapproved 2012)Standard Practice forPerformance Testing of Process Analyzers for AromaticHydrocarbon Materials1This standard is issued under the fixed designation D6621;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 practice serves as a practical guide for the perfor-mance testing of process stream analyzers specifically formeasuring chemical or physical characteristics of liquid aro-matic hydrocarbon materials for production or certification ofthese materials.The practice may be applicable to otherhydrocarbon stream analyzers as well.1.2 Only external methods(complete substitution of theprocess stream with a standard)of control sample introductionare included.Internal methods are beyond the scope of thispractice.1.3 Methods for resetting key operational parameters ofanalyzers to match predefined limits are provided by vendorsand are not included in this practice.1.4 Analyzer validation procedures are covered in PracticesD3764 and D6122,not in this practice.1.5 Procedures for statistically interpreting data from auto-matic sampling process stream analyzers are outlined.1.6 The implementation of this practice requires that theanalyzer be installed according to APIRP-550(1),2and be inagreement with the analyzer suppliers recommendations.Also,it assumes that the analyzer is designed to monitor thespecific material parameter of interest,and that at the time ofinitial or periodic validation,the analyzer was operating at theconditions specified by the manufacturer and consistently withthe primary test method.1.7 The units of measure used in this practice shall be thesame as those applicable to the test primary method used foranalyzer validation.1.8 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 use.2.Referenced Documents2.1 ASTM Standards:3D3764 Practice for Validation of the Performance of ProcessStream Analyzer SystemsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6122 Practice for Validation of the Performance of Multi-variate Online,At-Line,and Laboratory Infrared Spectro-photometer Based Analyzer SystemsE456 Terminology Relating to Quality and StatisticsE1655 Practices for Infrared Multivariate QuantitativeAnalysis3.Terminology3.1 Definitions:3.1.1 accuracy,ncloseness of agreement between a testresult and an accepted reference value.3.1.2 analyzer output,nsignal that is proportional to thequality parameter being measured and suitable for input toreadout instrumentation.3.1.2.1 DiscussionIt may be pneumatic,electrical,digital,etc.,and expressed as psi,mv,sec.,etc.3.1.3 analyzer result,nnumerical estimate of a physical,chemical,or quality parameter produced by applying thecalibration model to the analyzer output signal.3.1.4 bias,nthe difference between the expectation of theresults and an accepted reference value.3.1.5 control sample,nmaterial similar to the processstream that is stable over long periods of time so that itsparameters may be measured reproducibly in performance teststo characterize analyzer precision and accuracy.3.1.5.1 DiscussionMay be a pure compound,standardmixture,or a sample from the process stream.Its parameters1This practice is under the jurisdiction of ASTM Committee D16 on AromaticHydrocarbons and Related Chemicals and is the direct responsibility of Subcom-mittee D16.09 on On-Line Analysis.Current edition approved June 1,2012.Published August 2012.Originallyapproved in 2000.Last previous edition approved in 2006 as D6621 00(2006)1.DOI:10.1520/D6621-00R12.2The boldface numbers in parentheses refer to the list of references at the end ofthis practice.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 are used to plot statistical process control charts to defineanalyzer precision in normal operation.3.1.6 external performance testing,nprocedure involvingcomplete substitution of the process/product stream measuredby the analyzer with a control sample stream to measure theanalyzers precision and possibly accuracy(if the controlsamples true value is known).3.1.7 internal performance testing,nprocedure involvingthe addition of a known quantity of a standard materialhomogeneously into the process/product stream measured bythe analyzer to measure the analyzers precision and poss