大気中ガス濃度計測システム -CO_2レーザによる光音響変換ガス濃度測定システムについて(第3報)- [in Japanese] Development of Measurement System for Atmospheric Gas Concentration -Gas concentration measuring system by photoacoustic effect using CO_2laser(3rd Report)- [in Japanese]
Access this Article
Search this Article
In order to measure concentration of some kinds of gases flowing or emitting abruptly in underground space such as roadway in mine and tunnels, we have been studying a continuous and real time measurement system for gas concentration by means of a photoacoustic effect. In the previous papers, a calibration system and procedure to obtain the characteristics of photoacoustic signals, which was the relationships between gas concentration and photoacoustic intensity when CO2 laser was used, were examined. In this paper, we describe development procss and expermental results of new measurement system for atmospheric gas concentration changing with time. On the development process, the cooling system for laser discharge tube was converted from water circulation type to air circulation or electronic element cooling type to achieve the portability. Also, the doubletube type photoacoustic cell was improved to draw air in it for the continuous measurement of photoacoustic signals. Using the new systems, laboratory experiments were carried out to obtain the characteristics of the photoacoustic signals, and to compare the measurement accuracy of this system to the previous system. Consequently, we confirmed the availability of this new system in time response and in quantitative monitoring by the continuous measurement of CO2 gas in the atmosphere.
- Journal of MMIJ
Journal of MMIJ 115(2), 77-82, 1999-02-25
The Mining and Materials Processing Institute of Japan