A Trial of Smell Discrimination by SnO2 Gas Sensor
Akira FUJIMOTO, Takeshi KANASHIMA and Masanori OKUYAMA
Abstract:We have measured the SnO2 gas sensor response for several alcoholic and carboxylic gases to discriminate smells. The experimental results show that each alcoholic gas gave the peculiar response of the sensor and the secondary polarization of the gases molecules affected strongly to the transient response of the sensor. The total heats of formations were calculated by molecular orbital method using SnO2 cluster to examine the surface reaction of the sensor. The calculating results show that the adsorption distance of the gas molecular from the sensor surface affected to the sensor sensitivity. We operated the sensor heated by rectangular and triangular pulse voltages to discriminate several kinds of smell. The triangular pulse with a rise velocity of 43 [mV/sec] gave us the largest delay time difference for various alcoholic gases. These results suggest that the smell selective sensor will be realized by using the SnO2 gas sensor. Key Words:Gas sensor, SnO2, Smell discrimination, Molecular orbital method