METHOD FOR MEASURING MOISTURE CONTENT PERCENTAGE OF SNOW

PROBLEM TO BE SOLVED: To automatically measure a moisture content percentage of snow in non- contact manner by irradiating a snow with multiple infrared lights of different wavelengths for obtaining each reflection intensity ration, and referencing the mutual relationship between a preobtained reflection light intensity ratio and snow's moisture content percentage. SOLUTION: Infrared light of an infrared light source 31 is made, through BPFs 32 and 33, to be monochrome light of about 1,500nm which is ice's absorption wavelength and about 1,750nm which is common absorption wavelength of water and ice, and the BPFs 32 and 33 are fixed to as rotative disc 34, to be rotated with a motor 35. Infrared light is intermitted to be pulse light containing A.C. component, with the two kinds of monochrome light collimated with an irradiation lens 36, and the reflected light irradiated on a snow surface S is condensed with a light-receiving lens 37, for light-receiving with an infrared ray sensor 38. The output signal is, through a preamplifier 39, displayed on an oscilloscope 301, or taken into a computer 302 after A/D conversion, for obtaining a reflection light intensity ratio. This is substituted for a correlative regression expression representing pre-obtained moisture content percentage and intensity ratio, for obtaining a moisture content percentage, and displayed and recorded at a display/recording part 303.