Determination of Instantaneous Moisture Content and Moisture Potential Profiles PDF

For hygrothermal assessment of building envelopes, numerical simulation is increasingly used by the engineering practice. As the applied material functions have a strong influence on precision and information value of the simulation results, it is important to assess them on the basis of meaningful measurement data.

One method to obtain this kind of measurement data is the Instantaneous Profile Measurement technique introduced by Plagge (1991). It allows not only to determine moisture content profiles at different sample positions versus time, but also to measure the moisture potential (relative humidity or capillary pressure) at the same time. Thus this method is very suitable for assessing existing material models as well as improving and validating them.

This study briefly introduces the measurement method and explains the chosen experimental setup and its course. With two building materials different adsorption and desorption runs were carried out within the hygroscopic and wet moisture range. The obtained measurement results are shown and discussed. Their application for assessment of material functions is indicated within the discussion of the obtained results.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings X – December 2007

Units: SI