It is an optional module compatible with both the Q-Sense Explorer (previously Q-Sense E1) and Analyzer (previously Q-Sense E4) systems. The sensor surface is separated from the liquid flow by a Gore-membrane* thereby creating an air-filled compartment over the sensor. Flowing saturated salt solution over the membrane will generate a specific and controlled relative humidity in the volume above the sensor surface. The humidity above the sensor equilibrates almost instantly, providing the possibility of real time measurements.

Measurements are conducted in two steps:

1. The film of interest is applied to the sensor by, for example, spin-coating.
2. The coated sensor is placed in the module and vapor uptake or release is measured.

A typical application is to measure swelling of polymer or cellulose films.

*GORE is a trademark of W.L. Gore & Associates.