【英文标准名称】:Gasanalysis-Preparationofcalibrationgasmixturesusingdynamicvolumetricmethods-Part7:Thermalmass-flowcontrollers
【原文标准名称】:气体分析用动态容量法制备标定用混合气体第7部分：热质流控制仪
【标准号】:ISO6145-7-2001
【标准状态】:作废
【国别】:国际
【发布日期】:2001-04
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC158
【标准类型】:()
【标准水平】:()
【中文主题词】:校准气体;试验气体;气体分析;试样制备;控制样品;生产;容量分析;混合气体;物流率;热的;线环;流量调节阀;气体容量分析;准备;孔口;流动
【英文主题词】:Calibrationgases;Controlsamples;Eyelets;Flowregulators;Flows;Gasanalysis;Gasmixtures;Gas-volumetricanalysis;Massflowrates;Orifices;Preparation;Production;Specimenpreparation;Testgases;Thermal;Volumetricanalysis
【摘要】:ThispartofISO6145specifiesamethodforthecontinuousproductionofcalibrationgasmixtures,containingtwoormorecomponents,frompuregasesorothergasmixturesbyuseofcommerciallyavailablethermalmass-flowcontrollers.Byadjustmentofset-pointsonflowcontrollerstopre-determinedvalues,itispossibletochangethecompositionofthegasmixturerapidlyandinacontinuouslyvariablemanner.Byselectionofappropriatecombinationsofthermalmass-flowcontrollersandwithuseofpuregases,thevolumefractionofthecomponentofinterestinthecomplementarygascanbevariedbyafactorof1000.Therelativeexpandeduncertaintyofmeasurement,U,obtainedbymultiplyingtherelativecombinedstandarduncertaintybyacoveragefactor,k=2,isnotgreaterthan2%.Ifpre-mixedgasesareusedinsteadofpuregases,molefractionsbelow10canbeobtained.Themeasurementofmassflowisnotabsoluteandtheflowcontrollerrequiresindependentcalibration.Themeritsofthemethodarethatalargequantityofthegasmixturecanbepreparedonacontinuousbasisandthatmulti-componentmixturescanbepreparedasreadilyasbinarymixturesiftheappropriatenumberofthermalmass-flowcontrollersisutilized.Gasblendingsystems,baseduponthermalmass-flowcontrollers,andsomeincludingthefacilityofcomputerizationandautomaticcontrol,arecommerciallyavailable.
【中国标准分类号】:G85
【国际标准分类号】:71_040_40
【页数】:12P;A4
【正文语种】:英语