ASTM E96/E96M-22a

Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials

SIGNIFICANCE AND USE
5.1 The purpose of these tests is to obtain, by means of simple apparatus, reliable values for water vapor transfer rate through materials, expressed in suitable units.  
5.2 A WVTR value obtained in one method under one set of test conditions is not necessarily indicative of the value that would be obtained using the other method or under a different set of conditions. See Appendix X3 for discussion of determining dependency of WVTR on different relative humidity (at a given temperature).  
5.3 Commonly used test conditions are listed in Appendix X1, but given the above caution, the selection of test conditions other than those listed, and which closely approach exposure conditions of material in actual use, is allowed. Where tests are conducted for classification or compliance purposes, environmental conditions are typically defined in product standard specifications.
SCOPE
1.1 These test methods cover the determination of water vapor transmission rate (WVTR) of materials, such as, but not limited to, paper, plastic films, other sheet materials, coatings, foams, fiberboards, gypsum and plaster products, wood products, and plastics. Two basic methods, the Desiccant Method and the Water Method, are provided for the measurement of WVTR. In these tests, the desired temperature and side-to-side humidity conditions, with resultant vapor drive through the specimen, are used. The test conditions employed are at the discretion of the user, but in all cases, are reported with the results.  
1.2 The values stated in either Inch-Pound or SI units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, each system shall be used independently of the other. Derived results are converted from one system to the other using appropriate conversion factors (see Table 1).  
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, health, and environmental 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.

General Information

• Status: Historical
• Publication Date: 14-Oct-2022
• ICS: 77.040.99 - Other methods of testing of metals
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.33 - Insulation Finishes and Moisture

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E96/E96M − 22a
Standard Test Methods for
Gravimetric Determination of Water Vapor Transmission
1
Rate of Materials
This standard is issued under the fixed designation E96/E96M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 These test methods cover the determination of water
C168 Terminology Relating to Thermal Insulation
vapor transmission rate (WVTR) of materials, such as, but not
C1809 Practice for Preparation of Specimens and Reporting
limited to, paper, plastic films, other sheet materials, coatings,
of Results for Permeance Testing of Pressure Sensitive
foams, fiberboards, gypsum and plaster products, wood
Adhesive Sealed Joints in Insulation Vapor Retarders
products, and plastics. Two basic methods, the Desiccant
D449/D449M Specification for Asphalt Used in Dampproof-
Method and the Water Method, are provided for the measure-
ing and Waterproofing
ment of WVTR. In these tests, the desired temperature and
D2301 Specification for Vinyl Chloride Plastic Pressure-
side-to-side humidity conditions, with resultant vapor drive
Sensitive Electrical Insulating Tape
through the specimen, are used. The test conditions employed
E177 Practice for Use of the Terms Precision and Bias in
are at the discretion of the user, but in all cases, are reported
ASTM Test Methods
with the results.
E691 Practice for Conducting an Interlaboratory Study to
1.2 The values stated in either Inch-Pound or SI units are to
Determine the Precision of a Test Method
be regarded separately as standard. The values stated in each
3. Terminology
system are not necessarily exact equivalents; therefore, each
3.1 Definitions of terms used in this standard will be found
system shall be used independently of the other. Derived
in Terminology C168, from which the following is quoted:
results are converted from one system to the other using
“water vapor permeability—the time rate of water vapor
appropriate conversion factors (see Table 1).
transmission through unit area of flat material of unit thickness
1.3 This standard does not purport to address all of the
induced by unit vapor pressure difference between two specific
safety concerns, if any, associated with its use. It is the
surfaces, under specified temperature and humidity conditions.
responsibility of the user of this standard to establish appro-
Discussion—Permeability is a property of a material, but the
priate safety, health, and environmental practices and deter-
permeability of a body that performs like a material may be
mine the applicability of regulatory limitations prior to use.
used. Permeability is the arithmetic product of permeance and
1.4 This international standard was developed in accor- thickness.
dance with internationally recognized principles on standard- water vapor permeance—the time rate of water vapor
ization established in the Decision on Principles for the transmission through unit area of flat material or construction
induced by unit vapor pressure difference between two specific
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical surfaces, under specified temperature and humidity conditions.
Discussion—Permeance is a performance evaluation and not
Barriers to Trade (TBT) Committee.
a property of a material.
water vapor transmission rate—the steady water vapor flow
in unit time through unit area of a body, normal to specific
1
These test methods are under the jurisdiction of ASTM Committee C16 on
Thermal Insulation and are the direct responsibility of Subcommittee C16.33 on
2
Insulation Finishes and Moisture. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 15, 2022. Published November 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1953. Last previous edition approved in 2022 as E96/E96M – 22. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0096_E0096M-22A. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E96/E96M − 22a
A,B
TABLE 1 Units and Conversion Factors
6. Apparatus
To Obtain (for the
Multiply by
6.1 Test Dish—The test dish shall be of any noncorroding
same test condition)
material, impermeable to water or water vapor. There is no
...

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: E96/E96M − 22 E96/E96M − 22a
Standard Test Methods for
Gravimetric Determination of Water Vapor Transmission
1
Rate of Materials
This standard is issued under the fixed designation E96/E96M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 These test methods cover the determination of water vapor transmission rate (WVTR) of materials, such as, but not limited
to, paper, plastic films, other sheet materials, coatings, foams, fiberboards, gypsum and plaster products, wood products, and
plastics. Two basic methods, the Desiccant Method and the Water Method, are provided for the measurement of WVTR. In these
tests, the desired temperature and side-to-side humidity conditions, with resultant vapor drive through the specimen, are used.
Agreement is not to be expected between results obtained by different methods. The test conditions employed are at the discretion
of the user, but in all cases, are reported with the results.
1.2 The values stated in either Inch-Pound or SI units are to be regarded separately as standard. The values stated in each system
are not necessarily exact equivalents; therefore, each system shall be used independently of the other. Derived results are converted
from one system to the other using appropriate conversion factors (see Table 1).
1
These test methods are under the jurisdiction of ASTM Committee C16 on Thermal Insulation and are the direct responsibility of Subcommittee C16.33 on Insulation
Finishes and Moisture.
Current edition approved March 1, 2022Oct. 15, 2022. Published April 2022November 2022. Originally approved in 1953. Last previous edition approved in 20212022
as E96/E96M – 21.E96/E96M – 22. DOI: 10.1520/E0096_E0096M-22.10.1520/E0096_E0096M-22A.
A,B
TABLE 1 Units and Conversion Factors
To Obtain (for the
Multiply by
same test condition)
WVTR
2 2
g/h·m 1.43 grains/h·ft
2 2
grains/h·ft 0.697 g/h·m
Water Vapor Permeance (WVP)
2 –2
ng/Pa·s·m 1.75 × 10 perm
2 7
g/Pa·s·m 1.75 × 10 perm
2
perm 57.2 ng/Pa·s·m
–8 2
perm 5.72 × 10 g/Pa·s·m
Permeability
ng/Pa·s·m 0.688 perm-inch
8
g/Pa·s·m 6.88 × 10 perm-inch
perm-inch 1.45 ng/Pa·s·m
–9
perm-inch 1.45 × 10 g/Pa·s·m
A
These units are commonly used in the construction and building materials
industries. Additional units are used in other industries, such as packaging.
B
All conversions of mm Hg to Pa are made at a temperature of 0°C.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E96/E96M − 22a
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, health, and environmental 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. Referenced Documents
2
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C1809 Practice for Preparation of Specimens and Reporting of Results for Permeance Testing of Pressure Sensitive Adhesive
Sealed Joints in Insulation Vapor Retarders
D449/D449M Specification for Asphalt Used in Dampproofing and Waterproofing
D2301 Specification for Vinyl Chloride Plastic Pressure-Sensitive Electrical Insulating Tape
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of terms used in this standard will be found in Terminology C168, from which the following is quoted:
“water vapor permeability—the time rate of water vapor transmission through unit area of flat material of unit thickness induced
by unit vapor pressure difference between two specific surfaces, under specified temperature and humidity conditions.
Discussion—Permeability is a property of a material, but
...