To test the water vapor transmission rate (WVTR) of packaging materials, such as plastic film, composite film, coextrusion film, aluminum-plated film, aluminum foil, infusion bag, sheets, paper, paper board, solar battery panel, cellophane, ceramics and porcelain, and various containers such as bag, pouch, bottle, can, bowl, box, widely used in the industries of food, pharmaceuticals, personal care, household, electronics and so on.
Infrared detection sensor method. Fix the test sample in the middle of test chamber to separate the chamber into upper room and lower room. When humid gas flows in upper room and dry gas in lower room, the water molecules in upper room penetrate through the sample into the dry gas, and electrolytic sensor system detect and analyze the water content and calculate the water vapor transmission rate. To test container, humid gas is outside and dry gas is inside of the container.