Jan 05, 2021
ASTM D1653 standard and Test Method
ASTM D1653 standard determines the water vapor transmission rate of films of paint,lacquer,vanish, and other organic coatings. The films may be free films or be applied to porous substrates. Under ASTM D1653 standard, there are two test methods: dry cup method and wet cup method.
At the beginning of test, the dish may gains or loses weight quickly, and then goes into a constant rate of weight change. Certainly, the process depends on the material being tested.
Attention: By the wet cup method, the values obtained are higher than ones by the dry cup method under the same conditions of air temperature and humidity.
ASTM E96 standard and Test Method
ASTM E96 standard is used to test paper, plastic films, other sheet materials, fiber-boards, gypsum and plaster products, wood products, and plastics. ASTM E96 standard introduces two basic methods: the desiccant method and the water method.
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 gravimetric method to measure the water vapor permeability of materials.
