The method of water molecules counting during condensation process in the dew point detector

The paper presents a new method of water molecules counting during water condensation on the dew point detector surface. The method is based on the comparison of theoretical calculations and measurement results. The measurements were conducted in the special chamber able to keep the gas of demand humidity in a constant volume. The dependence of detector electrical parameters (the capacitance) in function of condensed on the detector surface water molecules number was determined. The relatively low detector output signal at the beginning of condensation can be explained with help of the previously published theoretical model of the capacitive humidity sensor. (C) 2011 Published by Elsevier Ltd.