سنسور گاز نوع جدید نیمه هادی برای کنترل کیفیت هوا در داخل کابین خودرو

A semiconductor type gas sensor for automobile ventilation control has been developed. A couple of tin dioxide based sensing materials, which were respectively sensitive to gasoline and diesel exhaust gases, were mounted on an alumina substrate with an integrated heater by using screen-printing technique. The sensor’s sensing element for diesel exhaust, which was heated at about 300°C, showed high sensitivity to NO2 (>0.5 ppm). The 63% response time to 1 ppm NO2 was approximately 12 s so that the sensor could rapidly detect diesel exhaust. Moreover, the sensor was selective to NO2 against coexisting gases such as CO or hydrocarbons. The sensor’s sensing material for gasoline exhaust also showed excellent sensing characteristics to gases in gasoline exhaust. By mounting two materials on a View the MathML source mm substrate, power consumption of the dual sensor could be reduced to about 360 mW also the sensor could be downsized. The sensor has high potential for air quality control in automobile cabins.

There are some devices to keep the air in automobile cabins clean by reducing the amount of pollutants flowing into the cabin. The amount of pollutants flowing into the cabin can be reduced by a trap with a charcoal filter or by automatic control of the air intake flap in air conditioning systems. Gas sensors are used to measure the amount of pollutants outside the cabin and control the air intake flap. The important pollutants are combustible gases such as CO and hydrocarbons emitted by gasoline-fueled engines and NO2 emitted by diesel-fueled engines. The concentration range of CO detection is from 10–100 ppm and that of NO2 detection is from 0.5–5 ppm. So, CO and NO2 sensors need to have high sensitivity to low concentration gases together with high selectivity. Moreover, quick response to gases is needed in order to avoid the inflow of the pollutants into the cabin. There are some reports concerned with CO and NO2 sensors for the air quality control in automobile cabins [1], [2], [3] and [4]. In this paper, we describe a new type of gas sensor for air quality control in automobile cabins. The sensor bas a couple of sensing materials suitable for exhaust gas detection. The evaluation results on sensing characteristics of the sensor will be given and discussed.

A new sensor with a couple of tin dioxide based sensing materials was developed. The power consumption of this sensor formed frome one View the MathML source mm substrate could be reduced to about 360 mW. The substrates were sensitive to NOx and combustible gases such as CO or hydrocarbons, respectively. Actually, the sensor showed excellent sensitivity to detection gases. Moreover, this sensor could quickly respond to exhaust gases. As a result, it was concluded that this sensor had a high potential for air quality control in automobile cabins.