The PERMATRAN-W series tests the WVTR of films as well as finished flexible and/or rigid plastic-based packaging. Model 3/33 Plus incorporates a patented, modulated infrared probe within the test cell. A high-precision sensor provides parts/million sensitivity. Any deviation from the desired set-point is automatically adjusted. Comes in 3 different master base control systems with 3 satellite modules—each providing different test capabilities for a maximum of 20 test cells/system.