| 1. ASTM E96 BW is the most commonly used standard. The test specimen is sealed to the open mouth of a test dish containing water and the assembly placed upside-down in a controlled atmosphere where the temperature is 23oC and the relative humidity is 50%. |
2.Periodic weighings determine the rate of water vapor movement through the specimen from the water to the controlled atmosphere. With inverted-cup method the water is in contact with the specimen. The result is indicated in g/m2x24hrs |
