Improvement of olfactory video camera: gas/odor flow visualization system

The “olfactory video camera” is a sensing system that helps locate a source of gas or odor. It consists of a portable homogeneous array of QCM gas sensors, and presents the visualized images of gas/odor flow reaching the array from the source location. In this paper, an improved version of the system is reported. A multichannel reciprocal frequency counter is implemented into a programmable LSI chip, and is employed to achieve a higher sampling rate of sensor responses while keeping the frequency resolution same as that of the conventional counter in the previous system. As a result, the temporal resolution of the visualized gas/odor flow has been improved and the maximum detectable flow velocity has been raised. The performance of the system has been tested in a clean room and a laboratory with regard to the system’s capability in capturing gas flow directions and pinpointing source locations. The experimental results have shown that the system can be applied in a variety of indoor environments.