1、Designation:D545411(Reapproved 2020)Standard Test Method forWater Vapor Content of Gaseous Fuels Using ElectronicMoisture Analyzers1This standard is issued under the fixed designation D5454;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revi
2、sion,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the watervapor content of gaseous fuels by the use of electro
3、nic moistureanalyzers.Such analyzers commonly use sensing cells basedon phosphorus pentoxide,P2O5,aluminum oxide,Al2O3,orsilicon sensors piezoelectric-type cells and laser based tech-nologies.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is
4、 theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on stand
5、ard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1142 Test Method for Water Vapor Content of Gaseo
6、usFuels by Measurement of Dew-Point TemperatureD1145 Test Method for Sampling Natural Gas(Withdrawn1986)3D4178 Practice for Calibrating Moisture Analyzers3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 capacitance-type cellthis cell uses aluminum coatedwith Al2O3as part of a ca
7、pacitor.The dielectric Al2O3filmchanges the capacity of the capacitor in relation to the watervapor present.Silicone cells also operate on this principal byreporting a capacitance change when adsorbing or desorbingwater vapor.3.1.2 electrolytic-type cellthis cell is composed of twonoble metal electr
8、ode wires coated with P2O5.Abias voltage isapplied to the electrodes,and water vapor chemically reacts,generating a current between the electrodes proportional to thewater vapor present.3.1.3 piezoelectric-type cellsensor consists of a pair ofelectrodes which support a quartz crystal(QCM)transducer.
9、When voltage is applied to the sensor a very stable oscillationoccurs.The faces of the sensor are coated with a hygroscopicpolymer.As the amount of moisture absorbed onto the polymervaries,a proportional change in the oscillation frequency isproduced.3.1.4 laser-type cellconsists of a sample cell wi
10、th anoptical head mounted on one end and a mirror mounted on theother;however,some models will not need a mirror to reflectthe light wavelength emitted from the laser.The optical headcontains a NIR laser,which emits light at a wavelength knownto be absorbed by the water molecule.Mounted,the laser is
11、 adetector sensitive to NIR wavelength light.Light from the laserpasses through the far end and returns to the detector in theoptical head.A portion of the emitted light,proportional to thewater molecules present,is absorbed as the light transits thesample cell and returns to the detector.3.1.5 wate
12、r contentwater content is customarily expressedin terms of dewpoint,F or C,at atmospheric pressure,or thenonmetric term of pounds per million standard cubic feet,lb/MMSCF.The latter term will be used in this test methodbecause it is the usual readout unit for electronic analyzers.One lb/MMSCF=21.1 p
13、pm by volume or 16.1 mgm/m3ofwater vapor.Analyzers must cover the range 0.1 to50 lb MMSCF.3.1.6 water dewpointthe temperature(at a specified pres-sure)at which liquid water will start to condense from thewater vapor present.Charts of dewpoints versus pressure andwater content are found in Test Metho
14、d D1142.1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.05 on Determination ofSpecial Constituents of Gaseous Fuels.Current edition approved Jan.1,2020.Published January 2020.Originallyapproved in 1993.Last previou
15、s edition approved in 2011 as D5454 111.DOI:10.1520/D5454-11R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3T
16、he last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Commit
