【英文标准名称】:StandardTestMethodsforWaterVaporContentofElectricalInsulatingGasesbyMeasurementofDewPoint
【原文标准名称】:用露点法测定电绝缘气体中水蒸汽含量的标准试验方法
【标准号】:ASTMD2029-1997(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:1997
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D27.07
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:adiabaticexpansion;aluminumoxide;chilledmirror;condensation;dewpoint;electricalinsulatinggas;fog;hygrometer;moisturecontent;SF6;siliconoxide;watervaporcontent;Dew/frostpoint;Electricalinsulatinggases;Watervaporcontent
【摘要】:Certaingaseshaveexcellentdielectricandelectricarcinterruptioncharacteristicswhichmaketheiruseinelectricalinstallationsverydesirable.Watercontent,asthetestparameter,isofgreatimportanceindeterminingthedielectriceffectivenessofthegas.Undercertainconditions,watermaycondenseandbecomeaconductingliquidresultinginacatastrophicdielectricbreakdownoftheinsulation.ThewatercontentoftheseinsulatinggasesasexpressedbydewpointislistedinSpecificationsD1933,D2473,andD3283.Oncethedewpointisdetermined,aconversiontomoisturecontentmaybeperformedusingTable1.Oncemoisturecontentisknown,thelowesttemperatureatwhichgasinsulatedequipmentcanbesafelyoperatedcanusuallybedeterminedbyreviewingmanufacturers''specificationsfortheequipment.Thedewpointofthetestgasisindependentofthegastemperaturebutdoesdependonitspressure.Manymoisturemeasurementtestinstrumentsaresensitivetopressure,anddisplaymoisturevaluesattheinstrumentinletpressureandnotnecessarilyatthepressureofthesystembeingsampled.Itisthereforeimportanttoaccountforthisconditiontoavoidseriousmeasurementerrors.TABLE1RelationshipBetweenDewPointandMoistureContentofGasesNote8212;Withaknowndewpointwhichisindicatedbythedewpointindicatororrecorder,themoisturecontentcanbereaddirectlyfromthetable.Thetableshowstheamountofwaterinairorothergasatvariousdewpointsatapressureof1atm(14.7)psi.DewPointMoistureContentDewPointMoistureContentx00B0;Cx00B0;Flb/1000ft3mg/LvolumeApercentx00B0;Cx00B0;Flb/1000ft3mg/LvolumeApercent50
122.0
5.16
82.7
12.2
x2212;16
3.2
0.079
1.27
0.149
49
120.2
4.92
78.9
11.6
x2212;17
1.4
0.072
1.16
0.136