Design of the Snow-Gauge Using Photoelectric Effects

Abstract

For hydroelectric power generation it is necessary to estimate the quantity of melt water flowing into the reservoir during the snow-thawing season. Up to this time the estimation was made with the snow gauge using radioactive isotope Co⁶⁰, but this method required strict control over the preservation and handling of the radioactive substance. Therefore, a new method for snow detection, using photoelectric effect instead of Co⁶⁰, was developed, and has been tested since 1973 in the area around Lake Towada.
In the new method, cadmium sulfide photoelectric cells are placed in a transparent polymethyl-methacrylate pipe, and the depth of snow is estimated by the amplitide of light detected. The weight of the snow must be converted into the corresponding amount of water, and a little error may be caused by the conditions of snow. Nevertheless, this method has advantages in that the equipment is simpler, the reliability is higher, and it is free of troublesome maintenance or handling. The method can be applied to various types of robot snow gauge.