MESH PLOT- BASED ANALYTICAL SELECTION OF OPTIMAL MQ-SERIES GAS SENSOR PARAMETERS

Abstract

ABSTRACT        

Metal Oxide Semiconductor or MOS-Type gas sensors are a type of sensors that can detect presence of some volatile, oxidizable or reducible substances in an environment. The sensitivity of these sensors depend on the selection of the appropriate parameters in terms of the sensor resistance in clean air () and the load resistance value (). A mesh plot analytical method for determing these parameters is presented in this paper. The model equation for MQ-135 sensor as a case study was derived and this was used to generate the mesh surface plot of the various relationships existing between the different parameters leading to the selection of the optimal value that can give a useful sensor output voltage. The mesh surface plot of (Ω), and concentration (ppm) and as well as the plot of,  and  were critically examined. The result of the simulation shows that, for optimal sensor output in MQ-135 sensor, the  value must be selected to be at a value of 30kΩ and the load resistor at a value of 47kΩ for effective sensor output.