Method and apparatus for infra-red moisture measurement

摘要

Disclosed herein an infrared moisture measuring apparatus which comprises a first infrared light-emitting diode (LED) for emitting infrared rays of a measuring beam whose infrared absorption varies by the moisture content of an object to be measured and a second infrared LED for emitting infrared rays of a reference beam whose infrared absorption does not substantially vary by the moisture content of an object to be measured. Also, an optical system is provided for illuminating the infrared rays of the measuring and reference beams emitted by the first and second infrared LEDs on the object and focusing the infrared rays reflected from the object, and an InGaAs light-receiving device is provided for receiving the infrared rays focused by the optical system and outputting a light-received signal which corresponds to a light quantity of the received infrared rays. The moisture value of the object is obtained based on the light-received signal output from the InGaAs light-receiving device. <IMAGE>