灰分儀進(jìn)口灰分儀灰分在線測量裝置廣州瑞發(fā)公司供應(yīng)高質(zhì)量灰分儀、灰分在線測量裝置。進(jìn)口灰分儀其精度和穩(wěn)定性均表現(xiàn)十分優(yōu)越。同時提供相似的國產(chǎn)灰分儀，品質(zhì)好，價格低?；曳謨x其主要原理特點(diǎn)用英文介紹如下： Continuousdeterminationofashincoalandincoalturbid MEASURINGPRINCIPLE灰分儀測量原理 Electro-magneticwaveslikeX-raysorgamma-raysareabsorbedinmaterialbydifferentways.Thereforeitdependsontheenergyoftheradiationandonthematerialitselfinwhichwayitisabsorbed.Highenergywavesandlowatomicnumbersareabsorbedaccordingtothedensity(orbulkdensity)ofthematerial.Ofcoursetheabsorption alsoisdependingonthelayerthickness.Thatmeanstheabsorptionisdependingontheweightofthematerial theradiationhaspassedthrough(Theweightincreasesifthewaybecomeslongerorifthedensitybecomeshigher).Densityandthicknesscanbemeasuredbymeansofradiations:Ifoneisconstanttheothercanbecalculated. Lowerenergyradiationandhigheratomicnumbersareabsorbedinthesamewaybutadditionalaccordingtothe atomicweight.Ashighertheatomicweightandaslowertheenergyashighertheabsorption. Foranalysispurposesaweakenergyisneededtodeterminetheatomiccomposition.Butalsotheweightisinfluencing theabsorption.Soahigherenergyradiationalsomustbeappliedtogetasignalwhichisinfluencedbytheweightonlybutnotbytheatomiccomposition.Bothsignalscanbeusedmathematicallytodeterminethecomposition. THETECHNIC灰分儀技術(shù)要點(diǎn) Tomeasureradiationitmustbeabsorbed.Theabsorptionishigherasmoredenstheabsorbermaterialis.There aregasfilledionisationchambersorGeigertubesavailablebutthemostsensitiveisacrystalofNaJwitha densityof3.7g/cm3.Thiscrystalproducesasmalllightflasheswhenexposedtoradiationwhichmust bedetectedbyalightamplifiercalledphoto-multiplier.Thewholedetectormustbebuildinamechanicalprotectionandlighttighthousingandalsostabelizedagainstanychanges. Thetwosourcesofradiationhavetobeshieldedinleadcontainerstopreventtheraystotravellinalldirections.Byathinchannelitisensuredthatonlyinonedirectiontheworkingbeamisallowedtocomeout.Theradiationismeasuredbyascintillationcounterwhichisthemostsensitivedetectoravailableforindustrialapplications. Both,sourceanddetector,iscalledmeasuringpath.Twomeasuringpathesarenecessaryforashdetermination. Itwouldbepossibletouseonlyonedetectorforbothradiationsbutbecausephysicallyinthedetectoreachradiations influencestheotheritismorereliabletouseseparateones. Eithersourceordetectorcanbeinstalledaboveorunderneeththebelt.Themeasuringpathesshouldhaveadistanceof1mminimumtoeachother.Afirmmechnicalframeisneededtopreventchangesofthedistancebetweensourceanddetector:Itmustbeabsolutellyconstanttoavoidmeasuringerrors. PRACTICALAPPLICATION灰分儀實(shí)際應(yīng)用 AradiationsourcewithCaesium-137isanemitterofrelativelyhighenergyradiation.Theenergyishighenough tobeindependentonthecompositionandlowenoughtohandleitinasecureway.Itisabletodeteminetheweightofthematerialwhichithaspassedthroughwithahighprecitionsothatforinstanceradiometricbeltscales areusingit. AnothermaterialemmitingradiationisAmericium-241.Thisenergyisquietelow:Asheetofsteelof0.8mmthickness isweakeningtheintensitytothehalf.IncoalthepartwhichiscalledashabsorbstheradiationoftheAm-241 muchmorethenthecarbon.Soahigherashcontentgivesanrelativlystrongincreaseoftheabsorption.Unfortunatellythereisnopracticalwaythatthisabsorptionisnotinfluencedbydensityorlayerthicknesse.g.loadingonabelt.Thereforebothsignalsareneededtogethertocalculatemathematicallythepercentageofash. THEEVALUATION Aprogramjustusinghighlysophisticatedmathematicsisnothelpingtheuser:Itmustbeappliable.Theashanalysermustbeabletobecalibratedwithoutextendedmathematicalbackground.Therforatableisstoredinthe evakuationunitwherelaboratoryvaluescanbestoredandusedascomparison.Aautomaticalroutinefordetermination ofthecalibrationcurvefindsthecoeffcientsandshowsimmidiatellyhowgoodthefitwas. Butnotonlythesimpledisplayofthemeasuringresultsisimportant.Theallreadymentionedtablecanbeused asadatastorage.Allmeasuringvaluesareshownoveratimeperiodof1hour,1shiftand1daybackfor30days. Intheservicemenuthesoftwareisabletochangethewiringterminalssothatarelayorananalogueoutput canbeswitchedfromoneterminaltoanother. Thereforetheevakuationunitisnotonlyandisplayofashbutfitsintotheprocessandcanhelpthocontroll it. ACCURACY灰分儀精度 Afewinfluencesareresponsibleforpossibleerrorsandgoodorbadaccuracy. Thecoalcommingfromonemineonlynormallyanaccuracyofbetterthen 0.5%standarderrorforabout10%ashalsowithcorsecoal.Forashcontentslowerthen10%evenbetterresultsareachieved.Forhigherashcontentstheerrorisbiggerbutnotbecauseoftheprinciplebutrelatedtothehighererrorofthelaboratories. Thesystemmustbecalibratedwithanerrorof0.3%causedbythelaboratotiesandthereforehasarestrictedaccuracy. Themostimportantpossibleerroriscausedbythecoalitself:Themeasuringprincipleisbasedondistinguishingtwocomponents.Inrealityitissomethingliketen.Anychangeofthecompositionoftheashcausesaslighterror.Becausethetwomaincomponentsdohavenearlythesameabsorptioncoefficientthisratiodoesnotcauseawrong indication.Theattentionmustbeputonchangeslikesuchinironcontent.Thetheoreticalerrorcanbeverybigbutisnotveryimportantinpractice.Neverthelessithastobeconsidered. Anothererrorcanbecausedbythemoisturecontent.Onlywhentheashcontentisabout5-10%isdoesnotcauseanerrorbecausewaterismeasuredascoal.Forhighercontentsiscancauseanerror.FortunatellythiscanbecompensatedforwithanRGImicrowavemoisturemeter.