Infrared moisture measuring apparatus

摘要: Apparatus for determining the content of moisture or other substance in a material by measuring its relative reflectance at two infrared wavelengths. A chopped radiation beam is produced arranging tuning fork such that an oscillating element alternatively moves first and second spaced optical bandpass filters having passband wavelengths into position to intercept source radiation. The directed on being analyzed, reflected therefrom applied detector. transmittances their are detector generates alternating pulses equal amplitude specified substance. also includes third filter zero transmittance which periodically interrupts so provides background signal used correct amplitudes pulses. separated ratio-determining circuit. output from feedback circuit regulating temperature