摘要 |
PROBLEM TO BE SOLVED: To provide an infrared moisture meter capable of measuring moisture percentage of an ultrathin paper highly accurately.SOLUTION: An infrared moisture meter comprises a light source part and a light receiving part which synchronously move with a paper to be measured laid between them, in which the light source part comprises a diaphragm plate in which a fine through-hole for allowing light created by mixing infrared rays having a plurality of wavelength to pass through and irradiate the paper is formed and a surface on the light receiving part is in a reflection surface. The light receiving part comprises a light shielding plate which faces the diaphragm plate and is arranged so as to allow light to pass through outside an outer periphery, and both surfaces of which are in reflection surfaces; and a reflector plate which is arranged at position farther from paper than the light shielding plate, a surface of which on a light source part side is in a reflection surface, and which has an outer diameter larger than the light shielding plate and leads light to a detector. |