Development of a SAW gas sensor for monitoring SO2 gas
Development of a SAW gas sensor for monitoring SO2 gas
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DOI：
10.1016/s0924-4247(98)80011-3
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发表时间：
1998-01-15
影响因子：
4.6
通讯作者：
Cho, HM
中科院分区：
文献类型：
--
作者：
Lee, YJ;Kim, HB;Cho, HM
我们将一种特殊的无机薄膜应用于SAW（表面声波）器件上，开发了一种新型SO2气体传感器。该传感器由一对中心频率为54 MHz的声表面波振荡器组成，由LiTaO3压电单晶制成。传感器的一条延迟线涂有一层CdS薄膜，可以选择性地吸附和解吸二氧化硫，而另一条延迟线没有涂覆，用作稳定的参考。采用超声喷嘴喷雾热解法制备了CdS薄膜。SO2气体吸附到CdS膜上引起的质量载荷和电场变化导致相应的频率位移与气体浓度成正比。用数字信号处理电路监测两个振荡器频率的相对变化。SO2传感器的性能包括灵敏度、响应时间和可重复性。该传感器作为一种微传感工具显示出良好的性能，能够测量空气中二氧化硫浓度低于200ppm。(C) 1998 Elsevier Science S.A.
We have developed a new type of SO2 gas sensor by applying a particular inorganic thin film on SAW (surface acoustic wave) devices. The sensor consists of twin SAW oscillators with a centre frequency of 54 MHz fabricated on LiTaO3 piezoelectric single crystals. One delay line of the sensor is coated with a CdS thin film that selectively adsorbs and desorbs SO2, while the other is uncoated for use as a stable reference. Deposition of CdS thin film has been carried out by the spray pyrolysis method using an ultrasonic nozzle. Mass loading and electric-field changes induced by the SO2 gas adsorbed onto the CdS film result in corresponding frequency shifts directly proportional to the gas concentration. The relative change in the frequency of the two oscillators is monitored with a digital signal-processing circuit. SO2 sensor properties investigated include sensitivity, response time and repeatability. The sensor shows promising performance as a microsensing tool and is capable of measuring concentrations in air less than 200 parts per billion of SO2. (C) 1998 Elsevier Science S.A.