mentinmeasurementprecisionislimitedandthecostofflowmetermayincrease,forthereasonthatthegas-liquidmixtureisnotfullyseparated,andthenumberofseorsanditrumentsneededisdoubled.themajordisadvantagesofnon-separatingmethodlieinthefactsthatalltheseorsanditrumentsaredirectlydiosedtothetwo-phaseflow,althoughsomeofthemarenon-intrusive.theviolentfluctuatioandflowpatternchangesoftwophaseflowwillmaketheseorsanditrumentsbefarlestable、reliableandprecisethanthatinsinglephaseflow,andevencannotworkatall.exceptfornuclearmagneticresonance(nmr)andradiotypetechniquessuchasa(pulsedneutronactivation),othernon-separatingmetersarelackofreasonabletheoreticalfoundatio.sofar,noneoftwo-phaseflowmeterscanmeetthecommercialstand:measuringerrorlethan±5,flowregimeindependent,andsuitableforuseinindustrialenvironment.nmrandaarehopeful,buttheyaretooexpeive(cost～%26#36;105－106)tobeusedinengineering.
thenewmethodproposedinthisthesisiscalled“extractingandseparatingmethodorareviatedtoesm”whichbreakthroughthepriormodels
ofgasliquidtwo-phaseflowmeasurement(separatingornon-separating).theproceisthat：first，proportionallyextractingastreamofgas-liquidmixture（5～20）fromthetwo-phaseflowtobemeasuredwithadistributor，thenseparatingitintosingle-phasegasandliquidwithasmallcompactseparator，afterthat，measuringeachphasewithconventionalsinglephaseflowmetersandconvertingthemeasuredvaluestothetwo-phaseflowratetobemeasuredaccordingtotheextractionratio，attheend,returningtheextractedstreamintothetwo-phaseflowpipeagain．becauseonl
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