介绍一种能检测0.0232 g/m3 CO的新型催化燃烧型传感器.这种传感器使用电阻温度系数高的负温度系数热敏电阻(NTCT)代替传统的铂丝线圈.传统的催化燃烧型传感器只能检测百分浓度的可燃气体,而基于NTCT的催化燃烧型CO传感器可以检测到0.0232 g/m3 CO气体.当桥电压为9V时,传感器输出信号与CO浓度在0.0232 ～0.58 g/m3之间具有良好的线性关系.传感器对0.58 g/m3 CO的响应和恢复时间分别为50和120 s.考察了传感器的选择性和长期稳定性,结果表明:传感器对甲烷等气体具有较好的选择性,老化处理后的传感器,连续观察100 d,对CO的响应强度未发生明显下降.%A novel catalytic combustion CO sensor which can be used to detect as low as 0. 023 g/m3 CO has been developed. The sensor is made of a negative temperature coefficient thermistor (NTCT) which has high temperature coefficient of resistance instead of a platinum coil. The traditional catalytic combustion sensor made of a platinum coil can only detect percentage levels of combustible gases, however, a catalytic combustion CO sensor based on a NTCT can detect as low as 0. 023 g/m3 CO. At the operating bridge voltage of 9 V, the linear relationship between the response signal and the CO concentration ranged from 0. 0232 to 0. 58 g/m3 is good. The 90% response and recovery times to 0. 58 g/m3 CO are 50 s and 120 s, respectively. Sensor selectivity and long-term stability are further investigated and discussed. The results indicate that the sensor has good selectivity to methane and other gases. In addition, aging of sensors did not significantly reduce the sensor sensitivity observed after continuously operation for 100 days.
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