ASTM E96/E96M-21

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. A WVTR value obtained under one set of test conditions is not necessarily indicative of the value under a different set of conditions. For this reason, the test conditions are to be selected that most closely approach the conditions of use. Commonly used conditions are shown in Appendix X1. 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. 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).  
1.3 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-Sep-2021
• 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 − 21
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.Anumber 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
1.1 These test methods cover the determination of water 2.1 ASTM Standards:
vapor transmission rate (WVTR) of materials, such as, but not C168Terminology Relating to Thermal Insulation
limited to, paper, plastic films, other sheet materials, coatings, C1809Practice for Preparation of Specimens and Reporting
foams, fiberboards, gypsum and plaster products, wood of Results for Permeance Testing of Pressure Sensitive
products, and plastics. Two basic methods, the Desiccant Adhesive Sealed Joints in Insulation Vapor Retarders
Method and the Water Method, are provided for the measure- D449/D449MSpecificationforAsphaltUsedinDampproof-
ment of WVTR. In these tests, the desired temperature and ing and Waterproofing
side-to-side humidity conditions, with resultant vapor drive D2301Specification for Vinyl Chloride Plastic Pressure-
through the specimen, are used. Agreement is not to be Sensitive Electrical Insulating Tape
expected between results obtained by different methods. The E177Practice for Use of the Terms Precision and Bias in
testconditionsemployedareatthediscretionoftheuser,butin ASTM Test Methods
all cases, are reported with the results. E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.2 The values stated in either Inch-Pound or SI units are to
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).
transmissionthroughunitareaofflatmaterialofunitthickness
1.3 This standard does not purport to address all of the
inducedbyunitvaporpressuredifferencebetweentwospecific
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—Permeabilityisapropertyofamaterial,butthe
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
Development of International Standards, Guides and Recom-
inducedbyunitvaporpressuredifferencebetweentwospecific
mendations issued by the World Trade Organization Technical
surfaces, under specified temperature and humidity conditions.
Barriers to Trade (TBT) Committee.
Discussion—Permeanceisaperformanceevaluationandnot
a property of a material.
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 Sept. 15, 2021. Published December 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1953. Last previous edition approved in 2016 as E96/E96M–16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0096_E0096M-21. 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 − 21
A,B
TABLE 1 Units and Conversion Factors
isdesirable.Ashallowdishispreferred,butitssizeandweight
To Obtain (for the
arelimitedwhenananalyticalbalanceischosentodetectsmall
Multiply by
same test condition)
weight changes. The mouth of the dish shall be as large as
WVTR
2 2
practical and at least 4.65 in. [3000 mm ] in area. The
2 2
g/h·m 1.43
...

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 − 16 E96/E96M − 21
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 (WVT) of materials through which the passage of
water vapor may be of importance, such as 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. The test methods are limited
1
to specimens not over 1 ⁄4 in. [32 mm] in thickness except as provided in Section 9. Two basic methods, the Desiccant Method
and the Water Method, are provided for the measurement of permeance, and two variations include service conditions with one
side wetted and service conditions with low humidity on one side and high humidity on the other. Agreement should not 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 method should be selected that more
nearly approaches the conditions of use.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 or inch-pound units are to be regarded separately as standard. The values
stated in each system mayare not benecessarily exact equivalents; therefore, each system shall be used independently of the other.
Combining values from the two systems may result in non-conformance with the standard. However, derived results can be
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 problems,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. 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
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, 2016Sept. 15, 2021. Published April 2016December 2021. Originally approved in 1953. Last previous edition approved in 20152016
as E96/E96M – 15.E96/E96M – 16. DOI: 10.1520/E0096_E0096M-16.10.1520/E0096_E0096M-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on 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 − 21
A,B
TABLE 1 Metric Units and Conversion Factors
To Obtain (for the
Multiply by
same test condition)
WVT
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 1 Perm (inch-pound)
2 7
g/Pa·s·m 1.75 × 10 perm
2
perm 57.2 ng/Pa·s·m
−8 2
1 Perm (inch-pound) 5.72 × 10 g/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 1 Perm inch
8
g/Pa·s·m 6.88 × 10 perm-inch
perm-inch 1.45 ng/Pa·s·m
−9
1 Perm inch
...