1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 15672:2000 ICS 83.
2、040.20; 83.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Rubber and rubber additives Determination of total nitrogen content using an automatic analyserThis British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals , w
3、as published under the authority of the Standards Committee and comes into effect on 15 October 2000 BSI 10-2000 ISBN 0 580 36516 6 BS ISO 15672:2000 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO 15672:2000 and implements i
4、t as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee PRI/23, Chemical testing of rubber, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the inte
5、rpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards wh
6、ich implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport
7、to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover
8、, the ISO title page, pages ii and iii, a blank page, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.INTERNATIONAL STANDARD ISO 15672 Firstedition 2000-07-15 Referencenumber ISO15672:2000(E) Rubberandrubberadditives Dete
9、rminationoftotalnitrogencontent usinganautomaticanalyser Caoutchouc et additifs pour caoutchouc Dosage de lazote total laide dun analyseur automatiqueISO15672:2000(E) ii ISO15672:2000(E)iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(IS
10、O memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnicalcom- mittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhasthe righttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,inliai- son
11、withISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnicalCommission (IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommittees
12、arecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthisInternationalStandardmaybethesubjectof patentrights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuc
13、hpatentrights. InternationalStandardISO15672waspreparedbyTechnicalCommitteeISO/TC45, Rubber and rubber products, SubcommitteeSC2, Testing and analyses.INTERNATIONALSTANDARD ISO15672:2000(E)1 RubberandrubberadditivesDeterminationoftotalnitrogen contentusinganautomaticanalyser WARNINGPersonsusingthisI
14、nternationalStandardshouldbefamiliarwithnormallaboratorypractice. Thisstandarddoesnotpurporttoaddressallofthesafetyproblems,ifany,associatedwithitsuse.Itisthe responsibilityoftheusertoestablishappropriatesafetyandhealthpracticesandtoensurecompliancewith anynationalregulatoryconditions. 1Scope ThisIn
15、ternationalStandardspecifiesaninstrumental(automaticanalyser)methodforthedeterminationoftotal nitrogeninrubberandrubberadditives. 2Termsanddefinitions ForthepurposesofthisInternationalStandard,thefollowingtermsanddefinitionsapply. 2.1 sample unitselectedtorepresentthematerialtobeanalysed 2.2 testpor
16、tion actualmaterialusedintheanalysis 2.3 controlsample materialwitharecognizedlevelofnitrogen,analysedwitheachsetoftestportions 3Principle 3.1Specifiedisareliable,rapid,instrumental(automatic)methodfordeterminingtotalnitrogeninrubberandrub- beradditives.Thenitrogenisdeterminedbyasingleinstrumentalpr
17、ocedureconsistingofweighingatestportion, placingitintheinstrumentandinitiatingthe(subsequentlyautomatic)analyticalprocess.Theanalysismaybecon- trolledmanuallytoalimiteddegree,andacapabilitytoperformcomputationsautomaticallymaybeprovidedbythe instrumentusedtoperformtheanalysis. 3.2Theactualprocesscan
18、varysubstantiallyfrominstrumenttoinstrumentbecauseavarietyofmeanscanbe usedtomeettheprimaryrequirementsofthemethod.Themethodincludesthefollowing: a)conversionofnitrogen-containingmaterialstonitrogenoxidesinanoxygenstream; b)reductionofthenitrogenoxidestoelementalnitrogenbypassingthemovercopperatanel
19、evatedtemperature; c)determiningthenitrogenbyoneofthreedetectionschemes. 3.3Inthethermalconductivitydetectionconfiguration,thecombustiongasesareconductedthroughaseriesof thermalconductivitydetectorsandgasabsorbersalignedsothatthegasespassfirstthroughthesamplesideofa watervapourdetector,throughawater
20、vapourabsorberandthroughthereferencesideofthedetector.Thegases arethenconductedthroughthesamplesideofacarbondioxidedetector,throughacarbondioxideabsorberandISO15672:2000(E) 2 throughthereferencesideofthedetector.Finally,theresultantgases,whichcontainonlynitrogenandthecarrier gas,passthroughthesample
21、sideofanitrogendetectorandarevented.Forthisdetector,high-puritycarriergasis usedasthereferencegas.Inthisway,thedetectorsdeterminethethermalconductivitiessolelyofthespecifiedcom- ponents. 3.4Inthecombinedabsorbance/conductivitydetectionconfiguration,thecarbondioxideandwatervapourare determinedbyinfra
22、reddetection,usinganaliquotofthecombustiongasesfromwhichonlythehalidesandsulfurox- ideshavebeenremoved.Thesedetectorsdeterminetheinfraredabsorbanceofthepertinentgasesatprecisewave- lengthwindowssothattheabsorbancesresultfromonlythespecifiedcomponents.Insuchasystem,nitrogenis determinedbythermalcondu
23、ctivity,usingasecondaliquotofthegasesadditionallytreatedtoreducethenitrogen oxidestonitrogenandtoremovetheresidualoxygen,carbondioxideandwatervapour. 3.5Inthemodifiedchromatographicdetectionconfiguration,whichisessentiallyamodifiedgaschromato- graphicsystem,thenitrogen,carbondioxideandwatervapourint
24、hetreatedcombustiongasesareelutedfroma chromatographiccolumnanddetermined(atappropriateretentiontimes)bythermalconductivitydetection. 3.6Theconcentrationofnitrogeniscalculatedineachconfigurationasafunctionofthefollowing: a)themeasuredinstrumental(automaticanalyser)responsesperunitmassforelementalnit
25、rogen(establishedvia instrumentcalibration); b)themassofthetestportion. 4 Requirementsforapparatus 4.1Becauseavarietyofinstrumental(automaticanalyser)componentconfigurationscanbeusedsatisfactorilyfor thismethod,nospecificationsarepresentedwithregardtooverallsystemdesign.Functionally,however,thefollo
26、w- ingrequirementsarespecifiedforallinstruments. 4.2Theconditionsforcombustionofthesampleshallbesuchthat(forthefullrangeofapplicablesamples) nitrogen-containingcomponentsshallbeconvertedcompletelytonitrogenornitrogenoxides.Generalinstrumental conditionsthataffectcompletecombustioninclude: a)availabi
27、lityoftheoxidant; b)temperature; c)time. 4.3Representativealiquotsofthecombustiongasesshallthenbetreatedtoreducenitrogenoxidestoelemental nitrogen. 4.4Fortheconfigurationdescribedin3.3,halides,sulfuroxidesandresidualoxygenareremovedwhenwater,car- bondioxideandnitrogenaredeterminedsequentially. 4.5Fo
28、rtheconfigurationdescribedin3.4,inwhichnitrogenisdetermined,water,carbondioxideandresidualoxy- genareremoved. 4.6Fortheconfigurationdescribedin3.5,halidesandsulfuroxidesareremoved. 4.7Thedetectionsystemshalldeterminenitrogenwithoutinterference. 4.8Thedetectorshouldideallyprovidealinearresponsethatco
29、rrelatesdirectlywithnitrogenconcentrationover thefullrangeofpossibleconcentrationsfromtheapplicabletestsamples. 4.9Thesystemshallincludeprovisionsforevaluatingnonlinearresponseappropriately,sothatnonlinearre- sponsescanbecorrelatedaccuratelywithconcentration.Suchprovisionscanbeintegralwiththeinstrum
30、entorbe providedby(auxiliary)computationschemes. 4.10Finally,exceptforthosesystemsinwhichthenitrogenconcentrationisexpressedasadirectoutput,thein- strumentshallincludeanappropriatedetectorresponsereadoutdevice.ISO15672:2000(E)3 5Reagents Reagentgradechemicalsshallbeusedinallanalyses,unlessotherwisei
31、ndicated. 5.1Helium,carriergas,asspecifiedbytheinstrumentmanufacturer. 5.2Oxygen,asspecifiedbytheinstrumentmanufacturer. 5.3Additionalreagents,asspecifiedbytheinstrumentmanufacturer. Thisspecificationreferstothereagentsusedtomeettherequirementscitedin3.3to3.5.Thesereagentscanvary substantiallyfordif
32、ferentinstruments;inallcases,however,thereagentsspecifiedbythemanufacturershallbe used. 6Instrument(automaticanalyser)preparationandcalibration 6.1Assembletheinstrumental(automaticanalyser)systeminaccordancewiththemanufacturersinstructions. 6.2Fortheresponse(drift)adjustment,weighandanalyse(inaccord
33、ancewiththemanufacturersinstructions)an appropriatetestportionofthenitrogencalibratingagent.Repeatthisprocedure,adjustinginstrumentresponseas recommendedbythemanufacturer,untiltheabsenceofdriftisindicated. 6.3Forthecalibration,selectcalibratingagentsandmaterialsspecifiedbythemanufacturerthathavecert
34、ified nitrogencontentslyingwithintherangeofthoseofthesamplestobeanalysed.Atleastthreesuchcalibratingagents arerecommendedforeachrangeofnitrogencontentstobedetermined.Whenpossible,twoofthecalibratingagents shallbrackettherangeofnitrogencontentstobedetermined,withthethirdfallingwithintherange. 6.4Fort
35、hecalibrationprocedure,analyseportionsofthecalibratingagentchosen(see6.3)torepresentthe nitrogencontentinthesamplestobetested.Continueanalysinguntiltheresultsfromfiveconsecutivedetermina- tionsfallwithintherepeatabilityinterval(see9.3)ofthismethod.Calibratetheinstrumentinaccordancewiththe manufactur
36、ersinstructionsusingthesevalues.Theresultsobtainedshallbewithintheprecisionlimitsstatedforthe calibratingagent,otherwisethecalibrationprocedureshallberepeated. 6.5Fortheperiodiccalibrationverificationandrecalibration,analyseacontrolsampleonaperiodicbasis.There- sultsobtainedforthecontrolsampleshallb
37、ewithinestablishedlimits.Ifnot,allresultsobtainedsincethelast successfulcontrolcheckshallberejectedandthecalibrationprocedurerepeated. 7Procedure Analyseatestportionofthesampleinaccordancewiththemanufacturersinstructions. Carryouttheanalysisinduplicate. 8Calculation Calculatethepercentnitrogen asfol
38、lows: where isthedetectorresponsefornitrogen; isthedetectorresponseperunitmassestablishedfornitrogenduringcalibration; N N= B C m 100% B CISO15672:2000(E) 4 isthemassofthetestportion,ingrams. 9Precision 9.1Althoughtheprecisionofthismethodwascalculatedfromdataobtainedfromtheanalysisofbituminouscoal t
39、hatcontainednitrogenintherange to ,itisconsideredtobedirectlyapplicabletotheanalysisfor nitrogeninrubbercompounds.TheprecisionisexpressedintermsasspecifiedinISO/TR9272,onthebasisofa confidencelevelforthevaluesestablishedforrepeatability andreproducibility . 9.2Theprecisiondatagiveninthisclausegivean
40、estimateoftheprecisionofthismethodwiththematerialsused intheparticularinterlaboratorytestprogramme.Theprecisionparametersshallnotbeusedforacceptanceorrejec- tiontestingofanygroupofmaterialswithoutdocumentationthattheparametersareapplicabletotheparticular groupofmaterialsandthespecifictestprotocolsof
41、themethod. 9.3Therepeatability,inpercentnitrogen,hasbeenestablishedasthevalueinTable1.Tworesults,obtainedin onelaboratory(sameinstrument,material,operator)undernormalprocedures,thatdifferbymorethanthistabulated valueshallbeconsideredtohavecomefromdifferentornon-identicalsamplepopulations. 9.4Therepr
42、oducibility ,inpercentnitrogen,hasbeenestablishedasthevalueinTable1.Tworesults,obtained indifferentlaboratories(samematerial,butdifferentinstrumentanddifferentoperator)undernormalprocedures,that differbymorethanthistabulatedvalueshallbeconsideredtohavecomefromdifferentornon-identicalsamplepop- ulati
43、ons. 9.5Biasiseliminatedwhentheapparatusiscalibratedproperlyagainstcertifiedreferencestandards.Propercali- brationincludescomparisonoftestdataoncalibratingagentsthathavecertifiednitrogencontents. 10Testreport Thetestreportshallincludethefollowinginformation: a)areferencetothisInternationalStandard;
44、b)alldetailsnecessaryforidentificationofthesampleanalysed; c)theprocedureused(thermalconductivitydetection,combinedabsorbance/conductivitydetectionormodified chromatographicdetection); d)theduplicatepercentnitrogenresultstothenearest ; e)theinstrument(automaticanalyser)makeandmodel; f) anydeviations
45、fromthemethod; g)thedateoftheanalysis. Table1Nitrogenanalysisprecision Withinlabs Betweenlabs 0,11 0,17 where istherepeatabilitystandarddeviation. where isthereproducibilitystandarddeviation. m 0,69% 1,57% 95% rR r R rR r=2,83 s r s r R=2,83 s R s R 0,1%ISO15672:2000(E)5 Bibliography 1ISO/TR9272:198
46、6, Rubber and rubber products Determination of precision for test method standards.BS ISO 15672:2000 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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