Moisture Management >> Moisture Vapor Transmission

Moisture Vapor Transmission

Test Method(s):
    · ASTM E96 - Procedure B

ASTM E96, Standard Test Methods for Water Vapor Transmission of Materials

Scope: Determination of Water Vapor Transmission of materials through which the passage of water vapor may be of importance, such as paper, plastic film, other sheet materials, fiberboards, gypsum and plaster products, wood products, and plastics.

  • Water method used at MSC
  • Unless specified the samples will be run at 50% Relative Humidity and 23oC
  • A cup is filled about half way with water. The sample is placed over the top of the cup and sealed with wax on the sides so as to allow the water vapor to evaporate through the sample.
  • The cup is placed on a rotating platform in a conditioned chamber and run for 24 hours unless otherwise specified. The samples are weighed periodically during the 24 hour period and a best fit line is achieved.
  • A Water/Moisture Vapor transmission rate is calculated in g/m2/24 hrs.
MVTR