Comparison of effectiveness of gas sensing by low frequency fluctuations in resistance and microbalance quartz gas sensors

Selectivity and sensitivity of gas sensing can be improved by fluctuation enhanced sensing. This possibility was investigated in resistive Taguchi Gas Sensors (TGS). Research results confirm that such an approach can strongly increase gas detection sensitivity. We suppose that low frequency fluctuations can be utilized to improve gas detection in other types of gas sensors. Fluctuations in the Quartz Crystal Microbalance (QCM) gas sensor for gas detection improving have been investigated. The sensor used in an experiment utilizes an ordinary quartz oscillator with a surface covered by a chemical layer absorbing humidity. The paper presents results of 1/f noise measurements in both types of sensors at different humidity. The prototype QCM sensor and resistive gas sensors of Figaro company were investigated. The results show advantages of this technique for future industrial applications.