Y. Tohjima et H. Wakita, DEVELOPMENT OF A CONTINUOUS MEASUREMENT SYSTEM AND AREAL DISTRIBUTIONOF METHANE IN SOME SOURCE AREAS, Applied geochemistry, 9(2), 1994, pp. 141-146
For the purpose of investigating the areal distribution of atmospheric
methane, we have constructed a continuous measurement system using a
flame ionization detector (FID). Since the FID has high sensitivity to
almost all hydrocarbons, non-methane hydrocarbons in sample air were
reduced by being passed through a heated column filled with Pt catalys
t. Through this treatment, non-methane hydrocarbons were effectively r
educed, and a low detection limit of 0.004 ppmv and short response tim
e of about 10 s were attained. By using this system mounted on a vehic
le, the areal distribution of atmospheric methane was measured in two
typical source areas: rice paddies and a natural gas field. In the cas
e of the gas field, we estimated the emission rate of methane based on
the observed profile of methane plumes.