Odor sensing characteristics of a lavatory in a general domicile

Six odor sensors, which are of the metal-oxide semiconductor type, were installed in a lavatory of a residence. Features of sensor-output patterns were investigated by monitoring the odors. Frequency of lavatory-use was detected and kinds of excretion were also identified. As for the results, it appears clear that two or three sensors react to urine and four or five sensors react to feces. The patterns, for example degree of fluctuation and inclination of sensor characteristics, differ with subjects. This system can be applied effectively to homes for the aged to survey the residents’ behaviors. The odor sensor system is also effective for monitoring the indoor environment without an infringement of privacy.