HR: 0800h
AN: A51C-0796    [Abstracts]
TI: Development of Atmospheric Methane Sensor based on Tin-Dioxide Flammable Detector
AU: * SUTO, H
EM: suto.hiroshi@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki,, 305-8506 Japan
AU: INOUE, G
EM: inouegen@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki,, 305-8506 Japan
AB: A new atmospheric methane sensor has been developed based on a tin-dioxide natural gas leak detector. The sensitivity, stability and selectivity to methane have been improved by the removal of water vapor in the sample air by chemical desiccant, by the stabilization of temperature by heater/Peltier cooler controller, and by the removal of other flammable gases by Pt-black catalyzer, respectively. The system is very compact in size (W$\times$D$\times$H = 200$\times$250$\times$200mm) and light in weight (4kg). The power consumption is less than 10W. The precision of measurement was examined for six NIES standard gases of CH4 in air in the range of 1800ppb to 2000ppb, and the residual error was found to be within $\pm$ 10ppb. The concentration of CH4 in the urban air was compared between the results by the GC/FID system with those of our system operated in parallel, and an excellent linear relationship with a standard error of 4ppb was observed. This system works continuously, but we must wait for several minutes before a reliable value is obtained when the methane concentration changes drastically, which seldom occurs even in the polluted environment. This system is precise and stable enough to monitor the methane in the baseline atmosphere.
DE: 1694 Instruments and techniques
DE: 1610 Atmosphere (0315, 0325)
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting