ASTM D4178-82(2017)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4178 − 82 (Reapproved 2017)
Standard Practice for
Calibrating Moisture Analyzers
This standard is issued under the fixed designation D4178; 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 2.1.2 By blending different volumes of the wet carrier gas
with dried carrier gas, gas standards of known water concen-
1.1 This practice covers a calibration technique based on the
tration can be prepared.
preparation of standards of known water content. This tech-
nique is applicable to the production of standards between 2.2 The moisture analyzer to be calibrated is then connected
3 3 3 3
20 cm /m and 2000 cm /m water. to the source of the gas standard of known water concentration.
1.2 The values stated in SI units are to be regarded as
3. Significance and Use
standard.
3.1 This practice is intended to provide a method to cali-
1.2.1 Exception—The values given in parentheses are for
brate moisture analyzers used on-stream or in the laboratory.
information only.
1.3 This standard does not purport to address all of the
4. Apparatus
safety concerns, if any, associated with its use. It is the
4.1 Ice Bath Primary Standard Moisture Apparatus—Fig. 1
responsibility of the user of this standard to establish appro-
illustrates a typical system.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.2 Wet Test Meter, 1 L divisions.
1.4 This international standard was developed in accor-
4.3 Bubble Meter, graduated in cubic centimetres.
dance with internationally recognized principles on standard-
4.4 Pressure Gauge—A Bourdon-type spring gauge of test
ization established in the Decision on Principles for the
gauge quality, 100 mm to 250 mm in diameter, with a scale
Development of International Standards, Guides and Recom-
range from 0 kPa to 400 kPa (0 psi to 60 psi), maximum
mendations issued by the World Trade Organization Technical
intermediate graduations of 1.5 kPa (0.25 psi).
Barriers to Trade (TBT) Committee.
4.5 Wet Mole Sieve 5A, 60/80 mesh (other mesh sizes may
2. Summary of Practice
be used, except powder).
2.1 The practice is based on the principle that ice has a
vapor pressure of 0.611 kPa at 0 °C. Therefore, when a carrier 5. Preparation of Apparatus
gas at a constant gauge pressure of 207 kPa (30 psig) is passed
5.1 Saturate mole sieve with water.
through a molecular sieve saturated with water and held at
5.1.1 Cover in beaker enough mole sieve to fill the wet mole
0 °C, the total pressure is equal to 207 kPa plus 98 kPa (one
sieve container. Add water to cover mole sieve. Let stand
atmosphere) and the water concentration of the gas leaving the
overnight.
molecular sieve is [0.611/(207 + 98)] × 10 ppm or 2000 ppm
5.1.2 Drain the excess water by pouring the mole sieve
volume water, regardless of flow.
slurry into a filtering funnel and letting all the free water drain
2.1.1 A carrier gas at a constant gauge pressure of 207 kPa
out.
is passed through a molecular sieve drier and then routed over
NOTE 1—The useful lifetime of the wet mole sieve is not known. It is
a molecular sieve support saturated with water and equilibrated
recommended that the procedure described in 5.1.1 and 5.1.2 be followed
at 0 °C.
prior to each calibration.
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum 6. Procedure
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
6.1 Fill the ice bath bucket for the primary standard appa-
mittee D02.D0 on Hydrocarbons for Chemical and Special Uses.
Current edition approved Oct. 1, 2017. Published November 2017. Originally ratus one third full of water; then add ice to bring the level to
approved in 1982. Last previous edition approved in 2012 as D4178 – 82 (2012).
full.
DOI: 10.1520/D4178-82R17.
For a more complete discussion of this procedure, see Mator, R. T., “Trace 6.2 Close the wet flow and the diluent flow needle values.
Moisture Analyzers and Their Calibration,” Proceedings of the 20th Annual ISA
6.3 Turn on the carrier gas supply (nitrogen or air) and
Analysis Instrumentation Symposium, May 12-15, 1974, Pittsburgh, PA, “Session:
Sampling and Calibration Systems,” 1974, p. 125. adjust the regulato
...

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: D4178 − 82 (Reapproved 2012) D4178 − 82 (Reapproved 2017)
Standard Practice for
Calibrating Moisture Analyzers
This standard is issued under the fixed designation D4178; 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 practice covers a calibration technique based on the preparation of standards of known water content. This technique
3 3 3 3
is applicable to the production of standards between 2020 cm /m and 2000 cm /m water.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.2.1 Exception—The values given in parentheses are for information only.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Summary of Practice
2.1 The practice is based on the principle that ice has a vapor pressure of 0.611 kPa 0.611 kPa at 0°C.0 °C. Therefore, when
a carrier gas at a constant gauge pressure of 207 kPa (30 psig) 207 kPa (30 psig) is passed through a molecular sieve saturated with
water and held at 0°C,0 °C, the total pressure is equal to 207 kPa plus 98 kPa 207 kPa plus 98 kPa (one atmosphere) and the water
concentration of the gas leaving the molecular sieve is [0.611/(207 + 98)] × 10 ppm or 2000 ppm ppm or 2000 ppm volume
water, regardless of flow.
2.1.1 A carrier gas at a constant gauge pressure of 207 kPa 207 kPa is passed through a molecular sieve drier and then routed
over a molecular sieve support saturated with water and equilibrated at 0°C.0 °C.
2.1.2 By blending different volumes of the wet carrier gas with dried carrier gas, gas standards of known water concentration
can be prepared.
2.2 The moisture analyzer to be calibrated is then connected to the source of the gas standard of known water concentration.
3. Significance and Use
3.1 This practice is intended to provide a method to calibrate moisture analyzers used on-stream or in the laboratory.
4. Apparatus
4.1 Ice Bath Primary Standard Moisture Apparatus —Apparatus—Fig. 1 illustrates a typical system.
4.2 Wet Test Meter, 1-L1 L divisions.
4.3 Bubble Meter, graduated in cubic centimetres.
4.4 Pressure Gauge—A Bourdon-type spring gauge of test gauge quality, 100100 mm to 250 mm 250 mm in diameter, with a
scale range from 0 to 400 kPa (0 to 60 psi), 0 kPa to 400 kPa (0 psi to 60 psi), maximum intermediate graduations of 1.5 kPa (0.25
psi).1.5 kPa (0.25 psi).
4.5 Wet Mole Sieve 5A, 60/80 mesh (other mesh sizes may be used, except powder).
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.D0 on Hydrocarbons for Chemical and Special Uses.
Current edition approved April 15, 2012Oct. 1, 2017. Published May 2012November 2017. Originally approved in 1982. Last previous edition approved in 20052012 as
D4178–82(2005).D4178 – 82 (2012). DOI: 10.1520/D4178-82R12.10.1520/D4178-82R17.
For a more complete discussion of this procedure, see Mator, R. T., “Trace Moisture Analyzers and Their Calibration,” Proceedings of the 20th Annual ISA Analysis
Instrumentation Symposium, May 12-15, 1974, Pittsburgh, PA, “Session: Sampling and Calibration Systems,” 1974, p. 125.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4178 − 82 (2017)
FIG. 1 Schematic of Ice Bath “Primary Standard” Moisture Apparatus
5. Preparation of Apparatus
5.1 Saturate mole sieve with water.
5.1.1 Cover in beaker enough mole sieve to fill the wet mole sieve container. Add water to cover mole sieve. Let stand overnight.
5.1.2 Drain the excess water by pouring the mole sieve slurry into a filtering funnel and letting all the free water drain out.
NOTE 1—The useful lifetime of the wet mole sieve is not known. It is recommend
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