EUROLAB laboratory provides testing and compliance services within the scope of ASTM E398 standard. The ASTM E398 standard covers the dynamic evaluation of water vapor transmission rate through a flexible barrier material and allows conversion into generally recognized water vapor transmission (WVT) units as obtained by various other test methods, including the gravimetric method described in Test Methods.
This test method is limited to flexible barrier sheet materials consisting of either purely hydrophobic materials or combinations of hydrophobic and hydrophilic materials with at least one surface that is hydrophobic.
A single set of test conditions cannot represent all climatic and usage conditions, so this WVTR test method serves to compare different materials under a specified set of conditions rather than predict their actual performance in the field under any given condition.
The water vapor transmission rate under known and carefully controlled conditions can be used to evaluate the vapor barrier properties of a layer. Direct correlation of values obtained under different test temperature and relative humidity conditions will be valid provided that the barrier material tested does not undergo changes in solid state (such as crystal transition or melting point) between or between test conditions.
The minimum test value obtained with this test method is limited to the leakage of water vapor through the compression seals of the tester. At 37.8 °C and 90% RH a reasonable value for any WVTR method, including the dryer procedure of Test Methods E96/E96M, would be about 0,01 g/24 h·m2. This limit can be checked for any instrument with an impermeable sample such as aluminum foil. Calibration procedures can compensate for the leak rate if specified.
This test method is currently not suitable for referee testing, but is suitable for control testing and material comparison.
Several other ASTM test methods are available for testing a similar property. This test method is unique in that it closely replicates typical product storage in which moisture transfer from a package to the environment is allowed without continuously vacuuming the surrounding side with dry gas.
Values stated in SI units should be accepted as standard. No other units of measurement are included in this standard.
This standard does not purport to address all, if any, safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.
Our organization, EUROLAB, provides standard test method services for the water vapor transmission rate of sheet materials using dynamic relative humidity measurement, within the framework of national and international standards, with its trained and expert staff and advanced technological equipment, among numerous test, measurement, analysis and evaluation studies. Provides testing services within the scope of ASTM E398 standard.
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EUROLABreporting and certification activities, United Accreditation Foundation (UAF), Turkish Accreditation Agency (TÜRKAK) ve Enterprise Accreditation Foundation (EAF) based on the accreditation provided by the accreditation body. The Enterprise Accreditation Foundation (EAF) accreditation body is also a signatory of the United Nations (UN GLOBAL COMPACT) organization.
