WVTRTests
WVTRTests are procedures used to determine the water vapor transmission rate through a material. WVTR measures how much water vapor passes through a defined area in a given time under controlled temperature and humidity. Values are typically expressed in g/m^2·day, with lower values indicating better barrier performance.
The two main methods are desiccant and humidity methods. In the desiccant method, one side of the
Standards: WVTR testing is commonly conducted to standards such as ASTM E96 and ASTM F1249, and equivalent
Interpretation and limitations: WVTR is affected by thickness, material composition, temperature, and humidity. Defects, improper seals,