ASTM D5454-11

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D5454–04 Designation:D5454–11
Standard Test Method for
Water Vapor Content of Gaseous Fuels Using Electronic
1
Moisture Analyzers
This standard is issued under the fixed designation D5454; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the determination of the water vapor content of gaseous fuels by the use of electronic moisture
analyzers. Such analyzers commonly use sensing cells based on phosphorus pentoxide, P O , aluminum oxide, Al O , or silicon
2 5 2 3
sensors piezoelectric-type cells and laser based technologies.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D1142 Test Method for Water Vapor Content of Gaseous Fuels by Measurement of Dew-Point Temperature
3
D1145 Test Method forFor Sampling Natural Gas
D4178 Practice for Calibrating Moisture Analyzers
D4888Test Method for Water Vapor in Natural Gas Using Length-of-Stain Detector Tubes Practice for Calibrating Moisture
Analyzers
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 capacitance-type cell—thiscellusesaluminumcoatedwithAl O aspartofacapacitor.ThedielectricAl O filmchanges
2 3 2 3
thecapacityofthecapacitorinrelationtothewatervaporpresent.UnlikeP O cells,thistypeisnonlinearinitsresponse.Ifsilicon
2 5
is used instead of aluminum, the silicon cell gives improved stability and very rapid response. film changes the capacity of the
capacitorinrelationtothewatervaporpresent.Siliconecellsalsooperateonthisprincipalbyreportingacapacitancechangewhen
adsorbing or desorbing water vapor.
3.1.2 electrolytic-type cell—thiscelliscomposedoftwonoblemetalelectrodewirescoatedwithP O .Abiasvoltageisapplied
2 5
to the electrodes, and water vapor chemically reacts, generating a current between the electrodes proportional to the water vapor
present.
3.1.3 piezoelectric-type cell— sensor consists of a pair of electrodes which support a quartz crystal (QCM) transducer. When
voltage is applied to the sensor a very stable oscillation occurs. The faces of the sensor are coated with a hygroscopic polymer.
As the amount of moisture absorbed onto the polymer varies, a proportional change in the oscillation frequency is produced.
3.1.4 laser-type cell— consists of a sample cell with an optical head mounted on one end and a mirror mounted on the other;
however, some models will not need a mirror to reflect the light wavelength emitted from the laser. The optical head contains a
NIR laser, which emits light at a wavelength known to be absorbed by the water molecule. Mounted along side Mounted, the laser
is a detector sensitive to NIR wavelength light. Light from the laser passes through the the far end and returns to the detector in
the optical head. A portion of the emitted light, proportional to the water molecules present, is absorbed as the light transits the
sample cell and returns to the detector.
3.1.5 water content—water content is customarily expressed in terms of dewpoint, °F or °C, at atmospheric pressure, or the
nonmetric term of pounds per million standard cubic feet, lb/MMSCF. The latter term will be used in this test method because it
1
This test method is under the jurisdiction of ASTM Committee D03 on Gaseous Fuels and is the direct responsibility of Subcommittee D03.05 on Determination of
Special Constituents of Gaseous Fuels.
Current edition approved Dec.June 1, 2004.2011. Published January 2005.July 2011. Originally approved in 1993. Last previous edition approved in 19992004 as
D5454–93(1999).D5454–04. DOI: 10.1520/D5454-04.10.1520/D5454-11.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Withdrawn.
3
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

------------------
...