Study of highly sensitive smell sensing system using gas detector tube combined with optical scanner

We describe rapid and low-cost system for monitoring bad smells in the living environment. This system consists of a conventional gas detector tube and an optical scanner. It was found that methyl mercaptan, hydrogen sulfide and propionaldehyde with the concentrations down to 29 ppb, 19 ppb and 46 ppb respectively were detectable. The sensitivity increased about 10 times larger than that of the conventional detector tube utilizing the accumulation effect. Moreover, we are currently developing a portable system using a one-dimensional CCD image sensor. The distribution of bad smell will be monitored using multiple portable sensors in the near future.