Abstract
•Optimization of micro gas sensor is done by design of experiment.•The impact of significant factors for detection SO2 by Knudsen force is revealed.•Comprehensive formula for mass analysis of dioxide sulfur in the mixture by MEMS actuator is presented.•Optimum condition for high precision detection of SO2 gas in the micro sensor is determined.
In this study, the Respond Surface Method (RSM) is applied to optimize the performance of the new micro gas actuator of MIKRA for analysis of the SO2 fraction in the mixture of the CH4-SO2. The impacts of effective factors such as pressure of domain, mass concentration of SO2 and temperature difference of arms are investigated to offer optimum condition for the high precision measurement of the SO2 gas in the SO2-CH4 mixture. Also, the overall performance correlation of MIKRA is presented to reveal the maximum Knudsen force in different operating conditions. Obtained results show that growing the operating pressure from 300 Pa to 1000 Pa increases three times the value of Knudsen force and this elevates the precision of this micro gas actuator for sensing SO2 gas in the natural gas. According to our findings, reduction of the gap size from 10 μm to 30 μm declines the net Knudsen force more than 2 times at specific SO2 concentration of φ=0.5. Our results demonstrate that increasing the pressure enhances the precision of the SO2 detection in this micro sensor.