ME™–Series Moisture Exchangers

ME™-Series moisture exchangers from Perma Pure are ideal for both drying and humidifying gas streams. This device uses Nafion® membrane tubing technology to transfer water to or from a gas stream. In either application, ME-Series moisture exchangers will act to achieve equilibrium between the gas inside the tubing and the surrounding atmosphere. This is done without loss of analytes and with no utility requirements.

Principle of Operation

In drying applications, ME-Series moisture exchangers transfer water vapor from a wet gas stream into the surrounding atmosphere. Drying is complete when the sample humidity level is equal to the ambient humidity level. Since drying proceeds as a First Order kinetic reaction, this level can be reached extremely quickly, usually within 100 to 200 milliseconds. This behavior makes the dryer ideal for applications involving a very humid sample at room temperature. Sample humidity can easily be reduced to as low as 10% of its original moisture content with only a short length of Nafion tubing.

For humidification, the ME-Series will transfer water vapor from the atmosphere to a dry gas flowing within the tubing. Once again, this process occurs in a fraction of a second and is very stable and repeatable under constant operating conditions. A common application is to humidify calibration gases, which allows calibration of analyzers at humidity levels equal to those seen in samples, providing a more consistent calibration/sample baseline.