Infrared ray moisture meter

An infrared ray moisture meter for measuring moisture contained in paper using absorption of infrared rays, said meter comprising

• an upper reflector having a return portion at a periphery thereof;
• a lower reflector having a return portion at a periphery thereof and disposed opposite said upper reflector with a space therebetween for paper to be measured for moisture content to be movable therethrough;
• a shielding plate having two mirror finished sides and disposed between said upper reflector and said lower reflector so as to comprise means for reflecting radiation that has passed through paper to be measured;
• means for applying to said paper infrared rays of a first wavelength range which are absorbed by moisture, infrared rays of a second wavelength which are absorbed by cellulose, and infrared rays of a third wavelength range which are absorbed by neither moisture nor cellulose;
• detecting means for detecting the infrared rays of said first wavelength range, the infrared rays of said second wavelength range, and the infrared rays of the third wavelength range, and for generating output signals corresponding thereto;
• and
• calculating means for calculating the value of moisture of the paper from the output signals from the detecting means.