ISO 00748-2021.docx
INTERNATIONA1.STANDARDISO748editionFifth2O21-1.1.HydrometryMeasurementof1.iquidf1.owinopenchanne1.sVe1.ocityareamethodsusingpointve1.ocitymeasurementsHydrometrieMesuragedudebitdesecou1.ementsasurfaceIibreMethodesd'exp1.orationduchampdesvitessesUti1.isantIemesragede1.avitesseparpointRSacncc7ttattH1.(E)COPYRIGHTPROTECTEDDOCUMENT©ISO2021IUirhM*hedbdi1.iUedotherwiseupdhi.o啪InyM1.ttti0oemhxitronio»ktu-Dkirietf1.vMqnIrHHBt1.Onmaytheinternetoranintranet,withoutpriorwrittenpermission.PermissioncanberequestedfromeitherISOattheaddressbe1.oworISO'smemberbodyinthecountr)oftherequester.f),WV>fifiU81.andonnet8CH-1214Vernier,GenevaPhone：M1.22749O1.11觥曲ite：图洲跳触OQrgPub1.ishedinSwitzer1.andContentsforewordScopeNormativereferencesTermsanddefinitionsPrincip1.eofthemethodsofmeasurementsSitese1.ection25.1 Se1.ectionofsite5.2 Demarcationofsite.Measurementofcross-sectiona1.area6.1 Genera1.36.2 Measurementofwidth3Measurementofmeanve1.ocity47.1 Determinationofmeanve1.ocityusingpointve1.ocitymeasurements47.1.1 Genera1.I7.1.3 Mfttiquttf1.conprQcedure47.1.4 Detenninationofthemeanve1.ocityinavertica1.57.1.5Integrdt1.onmethod.>>>>1.><，87.2 7erMW三8解蒯砒'fr°msuMaCeve1.Oei7.2.1 Genera1.87.2.2 Non-contactsystems94056922初瞬6f鲫SHm脚熟的W>g冲决加eterEXCRPt1.onS->>>>.<*«.MainsourcesoferrorComputationofdischarge8.1 Arithmeticmethods8.1.1 Genera1.8.1.3 M0>sfsstwnmethod108.1.4 Ba1.hymetricvertica1.s118.2 Independentvertica1.method11Uncertaintiesinf1.owmeasurement139.1 Genera1.139.2 Methodofca1.cu1.atingtheuncertaintyindischargebymeasurementofve!ocityrby9.2.2Contributoryuncertainties149.3 Methodofca1.cu1.atingtheuncertaintyindischargebymeasurementofve1.ocity8%ra1.169.3.2 Contributoryuncertainties169.3.3 Combineduncertaintyindischarge17MM堀网arianceestimatorQ胆_189.6 Q*199.7 F1.aure19Annex B (informative)Surfaceve1.ocitymeasurementusingf1.oats23Annex C (informative)Examp1.esurfaceve1.ocitysystems27Annex D (informative)Uncertaintiesintheve1.ocity-areameasurement._.一.一.29Annex E (informative)Ve1.ocitymeasurementundericeconditions32Annex F (mformative)Correctionsforwetted1.engthofwirewhenmeasuringdepthswithwirenotnorma1.tosurface38Bib1.iography41ForewordISO(theInternationa1.OrganizationforStandardization)isawor1.dwidefederationofnationa1.standardsBuchugh(ISOtnrhniroibirH)tR¼,kWpaphngbody1.ntnoi6tat(bW(no!hntart>edj<mitteehasbeenestab1.ishedhastherighttoberepresentedonthatcommittee.Internationa1.organizations,governmenta1.andnongovernmenta1.,in1.iaisonwithISO,a1.sotakepartinthework.ISOco1.1.aboratesc1.ose1.ywiththee1.ectrotechnica1.standardization.Internationa1.E1.ectrotechnica1.Commission(IEC)ona1.1.mattersofTheproceduresusedtodeve1.opthisdocumentandthoseintendedforitsfurthermaintenanceareeditoria1.ru1.esoftheISO/IECDirectives,Part2(seewww.iso.org/directives).R鹳MOn1.h1.sd做，刷姐n捣嫂黜树那馨ns心快梯田即侪斑相副刚的比咻跳墙临圈加陵subjectof搬1.三曲撼oSOIEC½teM福必曲硼眯蜘黜曲螂蝌e&cordancetheanypatentrightsidentifiedduringthedeve1.opmentCfbeintheIntroductionand/orAnytradeusedinthisontheISO1.istofpatentdec1.arationsreceived(secwww.iso.org/patents).constitutenameendorsement,domentisinformationgivenfortheconvenienceofusersanddoesnotForanexp1.anationofthevo1.untarynatureofstandards,themeaningofISOspecifictermsandinwj喃砌幅hnBa做Hsd幽S期www.iso.org/iso/foreword.htmI.刚v°do击碓INmM陋PremPedCOIbWJ腕外制COm曲feeEuro滥RS品味e(ydrom防Stah的hfiS界就都1.Technica1.CommitteeCkN/TC318,HydrometryfinaccordancewiththeAgreementontechnica1.cooperationbet¼reenISOandCEN(ViennaAgreement).脚氐88.hTfefimiVtFR触。WWtethef斓舸代。米,4曲邱(f9"WHfchhasbeentechnica1.1.y thedocumenthasbeenupdatedtotakeaccountoftechno1.ogica1.deve1.opments; C1.ause7hasbeenrevisedtoreduceuncertaintiesinmeasurements;一ISO9196regardingmeasurementundericeconditionshasbeenincorporated.雁品fifisHHI1.ieSthiscabg<fe1.1.ftstandardsbody.AHydrometryMeasurementof1.iquidf1.owinopenchanne1.sVe1.ocityareamethodsusingpointve1.ocitymeasurements1 Scopeinopenchanne1.sandforca1.cu1.atingthedischargeemp1.oyingpointve1.ocitymeasurementdevices.f1.oatsandothersurfaceve1.ocitysystems.pub1.icagenc1.es.deta1.1.edprocedures,refertoguide1.inesfromInstrumentmanufacturersandtheappropriate2 Normativereferencesconstitutesrequirements1.atesteditiondocument.referencedreferences,(inc1.udingamendments)app1.ies.app1.ies.ISO25377:2020,definitiOTXSuncertaintyguidance(HUG)Forthepurposesofthisdocument,thetermsanddefinitionsgiveninISO772app1.y.ISOOn1.inebrowsingp1.atform:avai1.ab1.eathHps:"WWWjSo.3¾obp4Princip1.eofthemethodsofmeasurementsThisischaracterizedasshownby-F0R4i-p4whereQThisdocumentspecifiesmethodsfordeterminingtheve1.ocityandcross-sectiona1.areaofwaterf1.owingItisapp1.icab1.etomethodsusingrotating-e1.ementcurren
