| 摘要 |
PROBLEM TO BE SOLVED: To provide a quantum-type infrared gas densitometer capable of stably performing measurement, with respect to the disturbance change, such as, flow rate change or temperature range of a measurement gas.SOLUTION: A signal processing part 120 inputs the sensor signal from a quantum-type infrared sensor through amplifiers 121a and 121b for applying the sensor signal and holds the off-level value of an infrared ray source from the sensor signal. Subtractors 123a and 123b subtract the off-level value held by the signal processing part and the signal inputted through the amplifiers. A section-setting device 126 sets a section outputting the power supply control signal of the infrared source and the infrared rays of the infrared source from the power supply control signal. Integrators 124a and 124b integrate the signals from the subtractors, on the basis of the signal of the section setting device. An operator 125 operators the ratio of the output signals of the respective integrators on the basis of the signal of the transmission quantity of light of the absorbing band of measuring target gas and the signal of the quantity of the transmission light of a wavelength band which does not absorb the measurement target gas. |
