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US:!:$("*US.HP4.PRSU\\H(#R@1/2A`Helvetica& i2PkC&P02A`HelveticaX:s2PkCXP($ DEEVd E d,rAZ*Helvetica Regular/xAp`Univers//xAp`Universx/ApUniversBold"4vAP`(UniversCondensed&4zAP2UniversCondensed BoldT Y.V=V,,&VgqT i2^C^,,X^ S2^C^,,/X^ p.V=V,,/&VTv.R=R,,f&RT R4%4,,J4 o.V=V,,&V~|-Q=Q&QbL(L:     L@LFl B !{ WPC-DY B BN!wŘ&/ApUniversBold"4vAP`(UniversCondensedH3|HM"u,ae^==\rr===r====rrrrrrrrrr==_rif3fzbmuur~n===\\=bibibBii,,b,iiii@\BifffXQ\Qrrrrrr=rrrrrr\rnbbbbbbibibibib3,3,3,3,iiiiiiiii~fbjii~fimicbcccbbyjcibibjcijiiiiii3,3,3,3,Xfzbc,c>b,cBc,j}jijiuBuBu@u\u\u\u\rIrBrBijiiji~fnXnXnXib,iu@u\rB~f~fyiiib3,,i4==\\==/N\rr=_ffrrsKKrFF\\rF==\\sDDsspp\\\~pp=\\F\a\巷 \==m=\rfs\=s\siwbzpNmń\QQ====؈fsbf\biUpNib3,z\_ffsNiimbmmQsU~bX~fiUi3,,i~bbbf~~===sssssssffffffffffffffffffffffUUUUUUUiiiiiiiiiiiiiiiiiiiiii,,,,,,,,,,,,iiiiiiibbbbbbbbbbbbi\Q="u,ae^CCd||ȘCCC|CCCC||||||||||CChȔ|so8okv|ȐxCCCddCkskskHss00k0ssssFdHsooo`YdY||||||C||||||d|xkkkkkĨksksksksk80808080sssssssssoktssosvslklllkktlsksktlstssssss80808080`okl0lDk0lHl0ttstsȵHHFdddd|P|H|HstsstsȬox`x`x`sk0sFd|Hoosssk800s4CCddCC/Nd||Choo||~QQ|LLdd|LCCdd~JJ~~zzdddzzCddLdjd dCCȐvȐCd|o~ȐȔdC~d~sȐkȐȐȤzȐUvŐdȐYYCCCCؔo~kodks]zUsk80dhoo~UssvkvvY~]k`os]s800skkkoCCC~~~~~~~oooooooooooooooooooooo]]]]]]]ssssssssssssssssssssss000000000000ssssssskkkkkkkkkkkksdYC"u,ae^CCh||ȘCCC|CCCC||||||||||CChȔ|so8okv|ȐxCCCddCkskskHss00k0ssssFdHsooo`ddd||||||C||||||d|xkkkkkĨksksksksk80808080sssssssssoktssosvslklllkktlsksktlstssssss80808080`okl0lPk0lNl8ttstsȵHHFdddd|\|H|HstsstsȬox`x`x`sk0sFd|Hoosssk800s4CCddCC/Nd||Choo|||QQ|LNdd|LCCdd|HH||xxdddxxCddLdod dCCȐxȐCd|v|ȣȔ`C|o|sȐdȐȐȬxȐUvŐdȐddCCCCؔs|vodssdx]sx84ddvo`sxvsx]|]vossds844svvsCCC|||||||ssssssssssssssssssssssdddddddssssssssssssssssssssss444444444444sssssssvvvvvvvvvvvvxdYC"u,ae^==_rr===r====rrrrrrrrrr==_rif3fzbmuur~n===\\=bibibBii,,b,iiii@\BifffX\\\rrrrrr=rrrrrr\rnbbbbbbibibibib3,3,3,3,iiiiiiiii~fbjii~fimicbcccbbjcibibjcijiiiiii3,3,3,3,Xfzbc,cIb,cHc3jjijiuBuBu@u\u\u\u\rTrBrBijiiji~fnXnXnXib,iu@u\rB~f~fiiib3,,i4==\\==/N\rr=_ffrrrKKrFG\\rF==\\rBBrrnn\\\~nn=\\F\f\巷 \==n=\rmrX=rfri~\znNmń\\\====؈irmf\ii\nUin30z\\mfXinminwUrU~mfii\i300i~mmiw~===rrrrrrriiiiiiiiiiiiiiiiiiiiii\\\\\\\iiiiiiiiiiiiiiiiiiiiii000000000000iiiiiiimmmmmmmmmmmmn\Q="u,ae^SSSSSSSSSSSEᵾ SSS}}SZ<<<אX}Z׋x}}}S}ҰE  @@L L !CERTIFICATIONOFGASEOUSCALIBRATIONSTANDARDS#XX##XXXX#  Y  М̛{XX September1997 #XXg# ] @@LL0̛̜@@ &{XX U.S.EnvironmentalProtectionAgency@@ &NationalExposureResearchLaboratory@@ HumanExposureandAtmosphericScienceDivision@@tt'ResearchTrianglePark,NC27711 #XX]¾#  &&{XX&&&&Ԝ   Ӝ /,0 Л &&@@..%EPATRACEABILITYPROTOCOLFORASSAYAND X @@  !CERTIFICATIONOFGASEOUSCALIBRATIONSTANDARDS#&&S #  K @@0@@..,@@+G&& G@@ &GXX&&GU.S.EnvironmentalProtectionAgency@@ &NationalExposureResearchLaboratory@@ HumanExposureandAtmosphericScienceDivision@@tt'ResearchTrianglePark,NC27711G GG#&&]#GGXX&&G#&&{XXœ#   МX"'"*h dh,p +  1  1  ̛8.,0 0  8  7XXd&&d7 Section!p(#Page  p  0X4 X0   4 ListofFigures"r(#. *ix  p     4 ListofTables"s(#. )x H     4 Acknowledgments"r(#.W*xi    М   4 Glossary>"p(#. #xiii  Л  1 4 INTRODUCTION"q(#. '11 X    28 4 EPATRACEABILITYPROTOCOLFORASSAYANDCERTIFICATION "X OFCOMPRESSEDGASCALIBRATIONSTANDARDS"q(#.B4421 "0 М   4 2.1 GENERALINFORMATION"q(#.2321 $    4  2.1.1 PurposeandScopeoftheProtocol"q(#.JK21 h%     4  2.1.2 ReferenceStandards"q(#.=21 @&!    4   2.1.2.1  GasManufacturer'sIntermediateStandard"q(#.\24 'h"    4   2.1.2.2  RecertificationofReferenceStandards"q(#.Z25 '@#    4  2.1.3 UsingtheProtocol"q(#.<25 ($    4  2.1.4 CertificationDocumentation"q(#. E25 )$    4  2.1.5 CertificationLabel"q(#.=26 x*%    4  2.1.6 Assay/CertificationofCompressedGasCalibration P+&    4   Standards"q(#.326 (,x'    4   2.1.6.1  IncubationofNewlyPreparedCompressed -P(    4     GasCalibrationStandards"q(#.M26     4   2.1.6.2  StabilityTestforReactiveGasMixtures"q(#.\26     4   2.1.6.3  CertificationPeriodsforCompressedGas `    4     CalibrationStandards"q(#.I27 8    4   2.1.6.4  MinimumCylinderPressure"q(#.M29 `    4   2.1.6.5  Assay/CertificationofMulticomponent 8    4     CompressedGasCalibrationStandards"q(#.X29      4  2.1.7 AnalyzerCalibration!p(#.f>210      4   2.1.7.1  BasicAnalyzerCalibrationRequirements!p(#.?[210 p     4   2.1.7.2  AnalyzerMultipointCalibration!p(#.S210 H      4   2.1.7.3  ZeroandSpanGasChecks!p(#.L213  p     4   2.1.7.4  ReferenceStandardsforMultipointCalibrations  H     4     andZeroandSpanGasChecks!p(#.TP214      4   2.1.7.5  UncertaintyoftheCalibrationCurve!p(#.X214      4  2.1.8 UncertaintyoftheEstimatedConcentrationof      4   theCandidateStandard!p(#.@215 X     4  2.1.9 ZeroGas!p(#.2217 0     4  2.1.10 AccuracyAssessmentofCommerciallyAvailable X    4   Standards!p(#.3217 0    4 2.28 PROCEDUREG1:ASSAYANDCERTIFICATIONOFA  COMPRESSEDGASCALIBRATIONSTANDARDWITHOUTDILUTION!p(#. (  218 @    4  2.1.1 Applicability!p(#.7218 h @54 TABLEOFCONTENTS (continued)  @ ̜ Section!p(#Page  x ̜   4  2.2.2 Limitations!p(#.\5218 (x Л   4  2.2.3 AssayApparatus!p(#.n9218 P    4  2.2.4 PollutantGasAnalyzer!p(#.I@220 (    4  2.2.5 AnalyzerCalibration!p(#.f>220      4   2.2.5.1  MultipointCalibration!p(#.J220  !    4   2.2.5.2  AnalyzerRange!p(#.B220 `!"    4   2.2.5.3  Linearity!p(#.=220 8"#    4   2.2.5.4  ZeroandSpanGasChecks!p(#.L221 #`$    4  2.2.6 AssayGases!p(#. 5222 #8%    4   2.2.6.1  CandidateStandard!p(#.jF222 $ &    4   2.2.6.2  ReferenceStandard!p(#.dF222 % '    4   2.2.6.3  ZeroGas!p(#.<223 p&!(    4  2.2.7 AssayProcedure!p(#.W9223 H'")    4  2.2.8 StabilityTestforNewlyPreparedCandidateStandards!p(#._224  (p#*    4  2.2.9 CertificationDocumentation!p(#. E225 (H$+    4  2.2.10 RecertificationRequirements!p(#.:F225 ) %,    4 2.38 PROCEDUREG2:ASSAYANDCERTIFICATIONOFA +&. COMPRESSEDGASCALIBRATIONSTANDARDUSINGDILUTION!p(#. (  225 0-(0    4  2.3.1 Applicability!l(#.5225     4  2.3.2 Limitations!l(#.\3225 x    4  2.3.3 AssayApparatus!l(#.n7226 P    4  2.3.4 PollutantGasAnalyzer!l(#.I>229 (x    4  2.3.5 AnalyzerCalibration!l(#.f<229 P    4   2.3.5.1  MultipointCalibration!l(#.H229 (    4   2.3.5.2  AnalyzerRange!l(#.@230      4   2.3.5.3  Linearity!l(#.;230  !    4   2.3.5.4  ZeroandSpanGasChecks!l(#.J230 `!"    4  2.3.6 SelectionofGasDilutionFlowRatesorGas 8"#    4   ConcentrationSettings!l(#.Z>232 #`$    4  2.3.7 FlowmeterTypeandFlowmeterCalibration!l(#.P232 #8%    4  2.3.8 AssayGases!l(#. 3233 $ &    4   2.3.8.1  CandidateStandard!l(#.jD233 % '    4   2.3.8.2  ReferenceStandard!l(#.dD234 p&!(    4   2.3.8.3  ZeroGas!l(#.:234 H'")    4  2.3.9 AssayProcedure!l(#.W7234  (p#*    4  2.3.10 StabilityTestforNewlyPreparedStandards!l(#.MS236 (H$+    4  2.3.11 CertificationDocumentation!l(#. C237 ) %,    4  2.3.12 RecertificationRequirements!l(#.:D237 *%-     +&.        38 4 EPATRACEABILITYPROTOCOLFORASSAYANDCERTIFICATION  OFPERMEATIONDEVICECALIBRATIONSTANDARDS"m(#.jD4431  ̛̜@51 TABLEOFCONTENTS(continued)  `  Section!l(#Page    ̜   4 3.1 GENERALINFORMATION"m(#.2231 H      4  3.1.1 PurposeandScopeoftheProtocol"m(#.JI31  p  Л   4  3.1.2 ReferenceStandards"m(#.;31  H     4  3.1.3 SelectingaProcedure"m(#.=32      4  3.1.4 UsingtheProtocol"m(#.:33      4  3.1.5 CertificationDocumentation"m(#. C33      4  3.1.6 CertificationLabel"m(#.;34 X     4  3.1.7 Assay/CertificationofCandidatePermeationDevice 0     4   CalibrationStandards"m(#.=34 X    4   3.1.7.1  PermeationDeviceDesign"m(#.J34 0    4   3.1.7.2  PrecautionsforUseandStorageof     4     PermeationDevices"m(#.mD34     4   3.1.7.3  EquilibrationofNewlyPreparedPermeation h    4     Devices"m(#.935 @    4   3.1.7.4  CertificationConditionsforPermeation h    4     DeviceCalibrationStandards"m(#.uN35 @    4  3.1.8 TechnicalVariances"m(#.b;35     4 3.28 PROCEDUREP1:ASSAYANDCERTIFICATIONOF x PERMEATIONDEVICECALIBRATIONSTANDARDSREFERENCEDTOAPERMEATIONDEVICEREFERENCESTANDARD"m(#. '  36 P    4  3.2.1 Applicability"m(#.536 (    4  3.2.2 Limitations"m(#.\336      4  3.2.3 AssayApparatus"m(#.n737  !    4  3.2.4 PollutantGasAnalyzer"m(#.I>39 `!"    4  3.2.5 AnalyzerCalibration"m(#.f<39 8"#    4   3.2.5.1  MultipointCalibration"m(#.H39 #`$    4   3.2.5.2  AnalyzerRange!l(#.@310 #8%    4   3.2.5.3  Linearity!l(#.;310 $ &    4   3.2.5.4  ZeroandSpanGasChecks!l(#.J310 % '    4  3.2.6 SelectionofGasDilutionFlowRates!l(#.L310 p&!(    4  3.2.7 FlowmeterTypeandFlowmeterCalibration!l(#.P310 H'")    4  3.2.8 PermeationDevices!l(#.J:311  (p#*    4   3.2.8.1  CandidateStandard!l(#.jD311 (H$+    4   3.2.8.2  ReferenceStandard!l(#.dD311 ) %,    4   3.2.8.3  ZeroGas!l(#.:311 *%-    4  3.2.9 AssayProcedure!l(#.W7312 +&.    4  3.2.10 StabilityTestforNewlyPreparedPermeation X,'/    4   Devices!l(#.\/314 0-(0    4  3.2.11 CertificationDocumentation!l(#. C314     4  3.2.12 RecertificationRequirements!l(#.:D315  М̛̛̜@51 TABLEOFCONTENTS(continued)  8  Section!l(#Page  p  ̜     4 3.38 PROCEDUREP2:ASSAYANDCERTIFICATIONOF  p  PERMEATIONDEVICECALIBRATIONSTANDARDSREFERENCEDTOACOMPRESSEDGASREFERENCESTANDARD!l(#. '  315      4  3.3.1 Applicability!l(#.5315   Л   4  3.3.2 Limitations!l(#.\3315 X     4  3.3.3 AssayApparatus!l(#.n7315 0     4  3.3.4 PollutantGasAnalyzer!l(#.I>317 X    4  3.3.5 AnalyzerCalibration!l(#.f<318 0    4   3.3.5.1  MultipointCalibration!l(#.H318     4   3.3.5.2  AnalyzerRange!l(#.@319     4   3.3.5.3  Linearity!l(#.;319 h    4   3.3.5.4  ZeroandSpanGasChecks!l(#.J319 @    4  3.3.6 SelectionofGasDilutionFlowRates!l(#.L319 h    4  3.3.7 FlowmeterTypeandFlowmeterCalibration!l(#.P319 @    4  3.3.8 CandidateStandard!l(#.G:320     4  3.3.9 ReferenceStandard!l(#.A:320     4  3.3.10 ZeroGas!l(#.0321 x    4  3.3.11 AssayProcedure!l(#.W7321 P    4  3.3.12 EquilibriumTestforNewlyPreparedPermeation (x    4   Devices!l(#.\/324 P    4  3.3.13 CertificationDocumentation!l(#. C324 (    4  3.3.14 RecertificationRequirements!l(#.:D324      4 3.48 PROCEDUREP3:ASSAYANDCERTIFICATIONOF `!" PERMEATIONDEVICECALIBRATIONSTANDARDSREFERENCEDTOAMASSREFERENCESTANDARD!l(#.F  324 #`$    4  3.4.1 Applicability!l(#.5324 #8%    4  3.4.2 Limitations!l(#.\3324 $ &    4  3.4.3 AssayApparatus!l(#.n7325 % '    4   3.4.3.1  AnalyticalBalance!l(#.D325 p&!(    4   3.4.3.2  TemperatureControlledChamber!l(#.P325 H'") М   4   3.4.3.3  ElectrostaticChargeNeutralization!l(#.QU327  (p#* Л   4  3.4.4 WeighingInterval!l(#.9327 (H$+    4  3.4.5 AssayProcedure!l(#.W7328 ) %,    4  3.4.6 NumberofWeighingsoftheCandidateStandard!l(#.U329 *%-    4  3.4.7 CalculationofCertifiedPermeationRate!l(#.P329 +&.    4  3.4.8 UncertaintyofCertifiedPermeationRatefor X,'/    4   CandidateStandard!l(#.G:331 0-(0    4  3.4.9 CertificationDocumentation!l(#. C331     4  3.4.10 RecertificationRequirements!l(#.:D331    40 4 REFERENCES"m(#. $4(#4(#41 ш  8            @51 TABLEOFCONTENTS(continued)   ̜ Appendix!l(#Page  `   A0 4 &&&&INSTRUCTIONSFORCALIBRATIONWORKBOOK#&&&&ϊ]#ԛ!m(#.N?4(#4(#A1     B0 4 INSTRUCTIONFORPERMEATIONRATEWORKBOOK"m(#.B4(#4(#B1 p    C0 4 CALCULATIONOFTOTALANALYTICALUNCERTAINTY!m(#. E4(#4(#C1  p    D0 4 &&&&MATRIXNOTATION "m(#.)4(#4(#D1#&&&&<_#ԛ       @8 LISTOFFIGURES   ?X x X4 #? Number!l(#Page  8 ̜   x 210  Exampleregressioncurveandconfidencebandsfrom8(#(# 0  0x (# (#0x(#x(#multipointcalibration!l(#.|1(#(#212      x 228  Onepossibledesignoftheapparatusfortheassayofcompressed p  gascalibrationstandardswithoutdilution(ProcedureG1)!l(#.xTJJ219 H      x 238  Onepossibledesignoftheapparatususingflowcontrollersfor  H  assayofcompressedgascalibrationstandardswithdilution(ProcedureG2)!l(#. )JJ227      x 248  Onepossibledesignoftheapparatususingagasdilutionsystem X  forassayofcompressedgascalibrationstandardswithdilution(ProcedureG2)!l(#. )JJ228 X    x 318  Onepossibledesignoftheapparatusfortheassayofpermeation  devicecalibrationstandardsreferencedtoapermeationdevicereferencestandard(ProcedureP1)"m(#.<JJ38 h    x 328  Onepossibledesignoftheapparatusfortheassayofpermeation h devicecalibrationstandardsreferencedtoacompressedgasreferencestandard(ProcedureP2)!l(#.<JJ316     x 33  Chamberformaintainingpermeationtubesatconstant x    x   temperature!l(#. &326 P М   x 340  Exampleofspreadsheetgraphicoutputforcalculatingpermeationrates!l(#.: a(#(#330 P   ( @#8 LISTOFTABLES    Number!l(#Page  8 ?X x X x ?   x 21  SUMMARYOFCOMPRESSEDGASSRMsTHATAREAVAILABLE 8    x   FROMNIST"m(#.t $22   М   x 220  SUMMARYOFCOMPRESSEDGASPRMsTHATAREAVAILABLEp (#(# 0  0x (# (#0x(#x(#FROMNMi"m(#.+ #(#(#23 H      x 238  CERTIFICATIONPERIODSFORCOMPRESSEDGASCALIBRATION  H  STANDARDSINALUMINUMCYLINDERSTHATARECERTIFIEDUNDERTHISPROTOCOL"m(#..JJ28      x 248  SOMELINEARIZINGTRANSFORMATIONSFORMULTIPOINT X  CALIBRATIONDATA!l(#.+JJ216 0     x 318  NISTSRMPERMEATIONDEVICEREFERENCESTANDARDS"m(#.uIJJ32 0    h 9X` X x 9@ 8 ACKNOWLEDGMENTS     TheinformationinthisdocumenthasbeenfundedwhollybytheU.S.EnvironmentalProtectionAgency(EPA)underContractNo.68D40091totheResearchTriangleInstitute(RTI),ResearchTrianglePark,NorthCarolina.  ThistraceabilityprotocolwaspreparedbyRobertS.WrightandMichaelJ.MessnerofRTIunderRTIProjectNo.91U6699208.Itisarevisionofanearlierprotocolthatwaspreparedin1993bythesameauthors.TheauthorsthanktheEPAworkassignmentmanager,BerneI.Bennett,forhisguidanceandtechnicaldiscussionastheprotocolwasbeingwritten.TheauthorsalsothankthefollowingRTIstaffmemberswhoprovidedadministrative,technical,editorial,wordprocessing,andgraphicartssupport:MalcolmJ.ϜBertoni,MichaelY.Cross,W.CaryEaton,TondaJ.Gentry,BerylC.Pittman,HelenM.Reading,SueS.Preston,andJanL.Shirley.̜ThisprotocolwasreviewedbypersonnelofEPA,theNationalInstituteofStandardsandTechnology(NIST),andtheNetherlandsMeasurementInstitute(NMi)asitwasbeingprepared.Theauthorswishtothankthefollowingindividualsfortheirtechnicalassistance:0  PamelaM.Chu(NIST) (#(# 0  EdW.B.DeLeer(NMi) (#(# 0  WillliamD.Dorko(NIST) (#(# 0  DavidL.Duewer(NIST) (#(# 0  GeraldD.Mitchell(NIST) (#(# 0  JohnT.Schakenbach(EPA) (#(# 0  RobWessel(NMi) (#(# Numerouscommentsfromspecialtygasproducersprovidedusefulcommentsandsuggestionsforrevisionstothisprotocol.Theauthorsthankthefollowingorganizationsfortheirassistance:0X` X 0  Airgas,Inc.̜0  AirLiquideAmericaCorporation (#(# 0  AirProductsandChemicals,Inc. (#(# 0  BOCGases (#(# М0  MathesonGasProducts (#(#   MGIndustries0  Praxair,Inc. (#(# 0  ScottMarrin,Inc. (#(#   ScottSpecialtyGases,Inc.0  SpectraGases,Inc. (#(#    (p#* М 2    3X` X` \3  /  xii  /0%  0@H GLOSSARY   ANSIAmericanNationalStandardsInstituteASTMAmericanSocietyforTestingandMaterials  `  GMISGasManufacturersIntermediateStandard 8 ILACInternationalLaboratoryAccreditationProgramISOInternationalStandardizationOrganizationNISTNationalInstituteofStandardsandTechnologyNmiNetherlandsMeasurementInstituteNTRMNISTTraceableReferenceMaterialNVLAPNationalVoluntaryLaboratoryAccreditationProgramPRMPrimaryReferenceMaterialRGMResearchGasMixtureSRMStandardReferenceMaterial  % ' Л-X` X -  7&&dX{Xd7  "X'XX"@ H SECTION1  X @9F INTRODUCTION   -X,` X - , In1993,theU.S.EnvironmentalProtectionAgency(EPA)inResearchTrianglePark,NorthCarolina,revisedits1987versionofitstraceabilityprotocolfortheassayandcertificationofcompressedgasandpermeationdevicecalibrationstandards.1,2󀀜Theprotocol  @ Мallowsproducersofgaseousstandards,usersofgaseousstandards,andotheranalyticallaboratoriestoestablishtraceabilitybetweentheirprotocolgasesandgaseousStandardReferenceMaterials(SRMs)producedbytheNationalInstituteofStandardsandTechnology(NIST).Parts50,58,60,and75ofTitle40oftheCodeofFederalRegulations(CFR)require P  usingSRMsorgaseousstandardstraceabletoSRMsforcalibratingandauditingambientairandstationarysourcepollutantmonitoringsystems.36 P   , &b&&&Astheprotocolwasbeingrevised,the1987versionwaspublishedintheJanuary11,  М1993,issueoftheFederalRegister.ItwasinsertedasAppendixHto40CFRPart75,whichconcernstheAcidRainProgram.InApril1996,EPA'sAcidRainProgramsuggestedthatthe1987and1993versionsoftheprotocolbeconsolidatedintoasingleprotocol.Indiscussionsatthattime,RTIsuggestedthattheprotocolberevisedinamannerthatwouldallowEPAProtocolGasestobeproducedeitherwiththehigheraccuracy(within2percent)neededbyEPAsAcidRainDivisionorwithlessstringentaccuracyrequirementsthatmightbeacceptabletootherusers.In1997,RTIsolicitedadditionalsuggestedrevisionsfromspecialtygasproducersandotherinterestedparties. , Thepurposeofthisworkassignmentwastorevisethestatisticalproceduresinthe1993versionoftheprotocolandtoconsolidateitstwopublishedversionsinordertomaketherevisedprotocolusefultoEPAsAcidRainDivisionaswellasotherusers.Improvementofthestatisticalprocedureshadthehighestpriority.#&&]&&b1#6X4P X,` 6     3X,` X43   , Thecurrentrevisionhasseveralsignificantchangesfromthe1993versionaslistedbelow:̜6,X, X,` 6 , 1.0  Statisticaltechniquesareusedtocalculatethetotaluncertaintyofthecandidate "0! Мstandard.Datafromthemultipointcalibrationandtheassaysareusedinthesecalculations(seeSection2.1.4); (#(# ̜ , 2.0  Theuncertaintyofreferencestandardsisnowincludedinthecalculationofthe @&!% totaluncertaintyofthecandidatestandard(seeSection2.1.2); (#(# ̜ , 3.0  Statisticaltechniquesareusedtocalculatethestabilityofcandidatestandards. ($( Theintermediateperformancestandardof1percentagreementbetweenassayshasbeendeleted(seeSection2.1.6.2); (#(# ̜ , 4.0  Statisticalspreadsheetsweredevelopedtoassistinthesecalculations,but (,x', equivalentstatisticaltechniquesmayalsobeused.Thesespreadsheetsreplace -P(- Мmostofthemanualcalculationsrequiredinthe1993versionoftheprotocol(seeAppendicesAthroughD). (#(# Ї , 5.0  Multipointcalibrationdatamaybefittedtostraightline,quadratic,cubic,orquartic  linearregressionmodelsbythespreadsheets,althoughtheuseofcubicandquarticmodelsisdiscouraged(seeAppendixA); (#(# ̜ , 6.0  Ifaquadraticorhigherordermodelisusedtofitthemultipointcalibrationdata,atleast ` tworeferencestandards,havingdifferentconcentrations,mustbemeasuredduringtheassays(seeSection2.2.7); (#(#  , 7.0  Thecorrectionforminorcalibrationdriftfollowingthemultipointcalibrationisembedded p  inthespreadsheetscalculationoftheuncertaintyofasingleassay; (#(#  , 8.0  PrimaryReferenceStandardsfromtheNetherlandsMeasurementInstitute(NMi)are  H  acceptedasbeingequivalenttoSRMsfromNIST(seeSection2.1.2); (#(#  , 9.0  Theanalystmaysubstitutealowconcentrationreferencestandardintheplaceofthe   zerogasduringassaysofthecandidatestandard(seeSection2.1.9); (#(# ̜ , 10.0  AsummaryofEPA'sauditresultsfrom1992tothepresentisavailableatanEPA X Мwebsite,http://www.epa.gov/ttn(seeSection2.1.10); (#(# ̜ , 11.0  Astripchartrecorderisnolongerrequiredaspartoftheassayapparatus,butahigh  precisiondataacquisitionsystemmustproduceanelectronicorpaperrecordoftheanalyzer'sresponseduringassays.Thisrecordmustbemaintainedfor3yearsafterthestandardscertificationdate(seeSection2.2.4). (#(#  1