Gas detection strategy to suppress flow rate interference baesd on semiconductor sensor dynamic temperature modulation measurement

Semiconductor gas sensors are widely used in industry, commerce and other fields. Flow rate has great influence on its response, but there was no breakthrough research progress at present. Usually, the interference is overcome by suppressing the expression of flow rate information at the output of the sensor. In this paper, a new research idea is put forward, which uses the ability of expanding output information of dynamic temperature modulation method to express the influence of flow rate on sensor. A typical case of butanone detection by SnO2 sensor was taken as the main experiment. By analyzing the microcosmic characteristic difference between flow rate and concentration in dynamic response, the change rule of dynamic response with flow rate change can be grasped, thus eliminating its interference to qualitative analysis. On the basis of dynamic temperature modulation, PCA and LDA are used to reduce the dimension of data, and the distribution law of two-dimensional score figure is obtained about the change of concentration and flow rate. In addition, the method is validated by using ethyl ether and toluene, and the same experimental phenomena are obtained. The results show that it is not only feasible but also has certain universality to use dynamic temperature modulation method to suppress the influence of flow rate on quantitative analysis.