A versatile inverse photopyroelectric (IPPE) technique and instrument for real time observation of the condensation of water vapor in the atmosphere.

A novel method and instrument capable of either monitoring continuously a condensation process or estimating the thickness of a liquid layer in the μm range are presented. The underlying physical principle is a variant of the photopyroelectric technique in which the changes in the thermal wave propagation due to the presence of the liquid layer are sensed by the pyroelectric sensor. The theoretical model developed supports the experimental results obtained. [ABSTRACT FROM AUTHOR]