(EN) PROBLEM TO BE SOLVED: To provide a gas concentration detector capable of appropriately detecting the concentration of a target gas in the gas to be measured, without having to frequently update calibration coefficients using a standard gas and a clean gas.
SOLUTION: A gas concentration detector 1 includes a calibration dimming filter 23F that causes light intensity 22OLI of emission light 22OL reaching an emitted light detection unit 24 to decrease. A signal processing unit 25 acquires a concentration ch of a target gas GJ in a gas GH to be measured, from: a calibration signal SC obtained when a gas container 22 is filled with a clean gas GA and the light intensity of emitted light is reduced by the calibration dimming filter; a clean gas signal SA obtained when the gas container is filled with the clean gas and the light intensity is not reduced by the calibration dimming filter; a measured-gas signal SH obtained in tandem with the calibration signal SC and the clean gas signal SA, and obtained when the gas container 22 is filled with the gas GH to be measured and the light intensity is not reduced by the calibration dimming filter; and a calibration coefficient kf given to the calibration dimming filter.
SELECTED DRAWING: Figure 1
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(JA)
【課題】頻繁に標準ガスと清浄ガスを用いて校正係数を更新しなくとも、適切に被測定ガス中の目標ガスの濃度を検知できるガス濃度検知装置を提供すること。
【解決手段】ガス濃度検知装置1は、出射光検出部24に届く出射光22OLの光強度22OLIを減少させる校正減光フィルタ23Fを備え、信号処理部25は、ガス容器22が清浄ガスGAで満たされ、かつ、校正減光フィルタで出射光の光強度を減少させたときに得られる校正信号SCと、ガス容器が清浄ガスで満たされ、かつ、校正減光フィルタによる減光を生じさせないときに得られる清浄ガス信号SAと、校正信号SC及び清浄ガス信号SAと相前後して得られ、ガス容器22が被測定ガスGHで満たされ、かつ、校正減光フィルタによる減光を生じさせないときに得られる被測定ガス信号SHと、校正減光フィルタに与えられた校正係数kfとから、被測定ガスGH中の目標ガスGJの濃度chを取得する。
【選択図】図1