| 초록 |
A semiconductor gas sensor based on SnO2 was studied at a low concentration range of chemical agent simulants such as acetonitrile, DMMP, DPM and dichloromethane from 0.02ppm to 0.8ppm at 350℃. The sensing properties of SnO2-based gas sensors such as sensitivity, response, recovery and reproducibility were investigated by using a flow measuring system. For acetonitrile and dichloromethane, P-SnO2 sensor prepared by precipitated SnO2 powder with small particle size and high surface area was more sensitive than C-SnO2 sensor prepared by commercial SnO2 powder with large particle size. While, in the cases of DMMP and DPM, the sensitivities of C-SnO2 sensor were higher than those of P-SnO2 sensor. These sensitivities of SnO2 sensors were closely related to the physical properties such as particle size, surface area, and pore size of the SnO2 powders in addition to the molecular sizes of the detecting gas. The recovery of SnO2-based sensors seemed to be possible for acetonitrile and DPM. However, in the cases of DMMP and dichloromethane, the complete recovery of SnO2-based sensors was impossible because of poisoning. |
