Investigation of heating profiles and optimization of power consumption of gas sensors for wireless sensor networks

Monitoring of hazardous and combustible gases at industrial premises and in the living apartments has been a topic of top priority for a number of decades. Within the last decade a great many of solutions have been proposed including the one relying on the Wireless Sensor Network (WSN) paradigm. Being an autonomous monitoring system, it is essential to guarantee a long lifetime of gas WSN. In this work, we are investigating and implementing a number of heating profiles for catalytic and semiconductor sensors used on board of the wireless sensor nodes to reduce their power consumption. After analyzing the pros and cons of these profiles, we propose the heating profile based on the Pulse Width Modulation (PWM) and the multi stage heating profile. Experimental results demonstrate that the average current consumption of the gas sensor node can be reduced up to 0.76 mA and its power consumption up to 2.54 mW thereby ensuring the autonomous operation of the sensing device for more than one year.