灰份仪进口灰份仪灰份在线测量装置广州瑞发公司供应高质量灰份仪、灰份在线测量装置。进口灰份仪其精度和稳定性均表现十分优越。同时提供相似的国产灰分仪，品质好，价格低。灰份仪其主要原理特点用英文介绍如下：ContinuousdeterminationofashincoalandincoalturbidMEASURINGPRINCIPLE灰份仪测量原理Electro-magneticw***eslikeX-raysorgamma-raysareabsorbedinmaterialbydifferentways.Thereforeitdependsontheenergyoftheradiationandonthematerialitselfinwhichwayitisabsorbed.Highenergyw***esandlowatomicnumbersareabsorbedaccordingtothedensity(orbulkdensity)ofthematerial.Ofcoursetheabsorptionalsoisdependingonthelayerthickness.Thatmeanstheabsorptionisdependingontheweightofthematerialtheradiationhaspassedthrough(Theweightincreasesifthewaybecomeslongerorifthedensitybecomeshigher).Densityandthicknesscanbemeasuredbymeansofradiati***:Ifoneisc***tanttheothercanbecalculated.Lowerenergyradiationandhigheratomicnumbersareabsorbedinthesamewaybutadditionalaccordingtotheatomicweight.Ashighertheatomicweightandaslowertheenergyashighertheabsorption.Foranalysispurposesaweakenergyisneededtodeterminetheatomiccomposition.Butalsotheweightisinfluencingtheabsorption.Soahigherenergyradiationalsomustbeappliedtogetasignalwhichisinfluencedbytheweightonlybutnotbytheatomiccomposition.Bothsignalscanbeusedmathematicallytodeterminethecomposition.THETECHNIC灰份仪技术要点Tomeasureradiationitmustbeabsorbed.Theabsorptionishigherasmoredenstheabsorbermaterialis.TherearegasfilledionisationchambersorGeigertubes***ailablebutthemostsensitiveisacrystalofNaJwithadensityof3.7g/cm3.Thiscrystalproducesa***alllightflasheswhenexposedtoradiationwhichmustbedetectedbyalightamplifiercalledphoto-multiplier.Thewholedetectormustbebuildinamechanicalprotectionandlighttighthousingandalsostabelizedagainstanychanges.Thetwosourcesofradiationh***etobeshieldedinleadcontainerstopreventtheraystotr***ellinalldirecti***.Byathinchannelitisensuredthatonlyinonedirectiontheworkingbeamisallowedtocomeout.Theradiationismeasuredbyascintillationcounterwhichisthemostsensitivedetector***ailableforindustrialapplicati***.Both,sourceanddetector,iscalledmeasuringpath.Twomeasuringpathesarenecessaryforashdetermination.Itwouldbepossibletouseonlyonedetectorforbothradiati***butbecausephysicallyinthedetectoreachradiati***influencestheotheritismorereliabletouseseparateones.Eithersourceordetectorcanbeinstalledaboveorunderneeththebelt.Themeasuringpathesshouldh***eadistanceof1mminimumtoeachother.Afirmmechnicalframeisneededtopreventchangesofthedistancebetweensourceanddetector:Itmustbeabsolutellyc***tantto***oidmeasuringerrors.PRACTICALAPPLICATION灰份仪实际应用AradiationsourcewithCaesium-137isanemitterofrelativelyhighenergyradiation.Theenergyishighenoughtobeindependentonthecompositionandlowenoughtohandleitinasecureway.Itisabletodeteminetheweightofthematerialwhichithaspassedthroughwithahighprecitionsothatforinstanceradiometricbeltscalesareusingit.AnothermaterialemmitingradiationisAmericium-241.Thisenergyisquietelow:Asheetofsteelof0.8mmthicknessisweakeningtheintensitytothehalf.IncoalthepartwhichiscalledashabsorbstheradiationoftheAm-241muchmorethenthecarbon.Soahigherashcontentgivesanrelativlystrongincreaseoftheabsorption.Unfortunatellythereisnopracticalwaythatthisabsorptionisnotinfluencedbydensityorlayerthicknesse.g.loadingonabelt.Thereforebothsignalsareneededtogethertocalculatemathematicallythepercentageofash.THEEVALUATIONAprogramjustusinghighlysophisticatedmathematicsisnothelpingtheuser:Itmustbeappliable.Theashanalysermustbeabletobecalibratedwithoutextendedmathematicalbackground.Therforatableisstoredintheevakuationunitwherelaboratoryvaluescanbestoredandusedascomparison.Aautomaticalroutinefordeterminationofthecalibrationcurvefindsthecoeffcientsandshowsimmidiatellyhowgoodthefitwas.Butnotonlythesimpledisplayofthemeasuringresultsisimportant.Theallreadymentionedtablecanbeusedasadatastorage.Allmeasuringvaluesareshownoveratimeperiodof1hour,1shiftand1daybackfor30days.Intheservicemenuthesoftwareisabletochangethewiringterminalssothatarelayorananalogueoutputcanbeswitchedfromoneterminaltoanother.Thereforetheevakuationunitisnotonlyandisplayofashbutfitsintotheprocessandcanhelpthocontrollit.ACCURACY灰份仪精度Afewinfluencesareresp***ibleforpossibleerrorsandgoodorbadaccuracy.Thecoalcommingfromonemineonlynormallyanaccuracyofbetterthen&plu***n;0.5%standarderrorforabout10%ashalsowithcorsecoal.Forashcontentslowerthen10%evenbetterresultsareachieved.Forhigherashcontentstheerrorisbiggerbutnotbecauseoftheprinciplebutrelatedtothehighererrorofthelaboratories.Thesystemmustbecalibratedwithanerrorof0.3%causedbythelaboratotiesandthereforehasarestrictedaccuracy.Themostimportantpossibleerroriscausedbythecoalitself:Themeasuringprincipleisbasedondistinguishingtwocomponents.Inrealityitissomethingliketen.Anychangeofthecompositionoftheashcausesaslighterror.Becausethetwomaincomponentsdoh***enearlythesameabsorptioncoefficientthisratiodoesnotcauseawrongindication.Theattentionmustbeputonchangeslikesuchinironcontent.Thetheoreticalerrorcanbeverybigbutisnotveryimportantinpractice.Neverthelessithastobec***idered.Anothererrorcanbecausedbythemoisturecontent.Onlywhentheashcontentisabout5-10%isdoesnotcauseanerrorbecausewaterismeasuredascoal.Forhighercontentsiscancauseanerror.FortunatellythiscanbecompensatedforwithanRGImicrow***emoisturemeter.)