An experimental investigation was made of the water content of porous materials, which affects physical, physicochemical, and chemical processes. The investigation was based on the fact that water vapour and drops present in the pores of a material can influence the scattering of light by its surface when it is illuminated with a narrow low-intensity laser beam. Measurements were made of the intensity of He-Ne laser radiation reflected by the surface of a moist material (moist gypsum slurry with an internal structure of different types). The scattered-light intensity increased on reduction of the water content of porous materials. [Journal Article; Translated from: Kvantovaya Elektronika, Moskva; Coden: KVEKA3; ISSN: 03687147; Volume 25, Issue 7; Russia; Pages 741-744; July 1995; 12 Refs]

• measurement: laser
• measurement: moisture content

1. Non-contact methods of measuring moisture concentration in external layers of building partitions. I--The influence of geometrical microstructure on the kinetics of moisture condensation on glass surfaces