We describe a computerized microscope system that has been developed for studying the physics of dust particles which adhere to various kinds of surfaces such as those of solar collectors. The device enables investigators: (I) to obtain the particle size distribution of dust on a Surface; (2) to calculate the fraction of surface area covered by dust; (3) to calculate the reduction of optical efficiency (of the solar collector under study) as a function of particle size; (4) to investigate the effect of various kinds of applied force field on the adhesion of dust particles to the surface. Some examples are given for the use of such a measuring system for the study of photovoltaic and solar-thermal collector surfaces.