基于Lamb波气体传感器的数据采集仪

Lamb波气体传感器因其具有高灵敏度、低损耗、多模式特性,在气体传感领域中展示出十分广阔的工业应用前景。然而,迄今为止,Lamb波气体传感器尚处于实验室基础研究阶段,其测试是基于网络分析仪,需人工读取测试结果并计算,不能实现自动获取被测参数,这在很大程度上限制了传感器的实际应用。针对现有测试技术的不足,研制了一种针对Lamb波气体传感器的数据采集仪。利用直接数字频率合成技术和嵌入式技术获取传感器的幅频特性和相频特性,通过多峰值快速搜索算法提取各个模式的最大峰值信息,并对传感器进行了各个模式下的扫频测试实验和算法验证实验。实验结果表明,采集仪能准确获得传感器的频率特性数据,并能实现一定频率范围内多个峰值信息的获取。再结合气体测量的相关模型,可直接输出参数测量结果,实现气体参数的自动检测。

Data acquisition instrument based on Lamb wave gas sensor

Lamb wave gas sensor has broad industrial application prospects in gas sensing due to its advantages of high sensitivity,low loss and multi-mode characteristic. However,Lamb wave gas sensor is now still in fundamental academic research period. Experiments concerning the sensor are implemented by network analyzers,which means that gas properties cannot be determined automatically but by manual operation. This limits the applications of Lamb wave gas sensor. In this paper,a specified data acquisition instrument designed for Lamb wave gas sensor was developed. The direct digital synthesizer technology and an embedded system were introduced to obtain the information of the amplitude-frequency and phase-frequency of Lamb wave gas sensor. Maximum peaks of all Lamb wave modes were determined by a multi-peak fast search algorithm. To verify the effectiveness of the data acquisition instrument,frequency sweep experiment and algorithm verifi-cation experiment were carried out under different modes. The experimental results show that the data acquisi-tion instrument can accurately acquire the frequency characteristics of Lamb wave gas sensor and the informa-tion of multiple peaks in a certain frequency range. Then,combining with the models of Lamb wave gas sens-ing,it can directly output parameter measurement results,and achieve automatic detection of gas parameters.