ASTM E96 Standard and Test Method
ASTM E96 standard is used to test paper, plastic films, other sheet materials, fibre-boards, gypsum and plaster products, wood products, and plastics. ASTM E96 standard introduces two basic methods: the desiccant method and the water method.
ASTM E96 Desiccant Method
The desiccant method: the test dish contains a desiccant. Leave enough space so that the shaking of the dish to mix the desiccant, which has to be done at each weighing. The test specimen is sealed to the open mouth of the dish. The rate of water vapor movement is determined by periodic weighing of the test dish.
ASTM E96 Water Method
The water method: the dish contains distilled water. Water vapor permeates through the specimen into the controlled atmosphere. Through the periodic weighing of the test dish, the values can be obtained.
ASTM E96 Test Method Attention
Under different test conditions, the valued obtained may not be equivalent. As this reason, select the test conditions which are the closest with the conditions of use.
Desiccant method and water method are generally called gravimetric method. Saicheng’ WPT-301B Water Vapor Permeability Tester which is manufactured with ASTM E96 standard and ASTM D1653 standard adopts a gravimetric method to measure the water vapor permeability of materials.