CH4 Monitoring with Ultra-Low Power Wireless Sensor Network

We propose a novel method to reveal and measure natural gas presence in air, using commercial off-the-self available MOX gas sensors in wireless sensor network applications. This technique reduces the power consumed by the catalytic sensors of a factor 10x, by an analysis on a reduced sampled period and thus extending the autonomy of battery operated systems. The information about the gas concentration is extracted from the sensor transient response through a discrete cosine transform (DCT) analysis and permits to immediately discriminate between clean-air and hazardous situations. The characterization of the sensing device has been conducted using a wide range of humidity and environmental conditions to demonstrate the effectiveness of the approach and a detailed comparison with the standard usage has been performed. Finally, the technique has been implemented in a Wireless Sensor Network designed specifically to measure air-quality in a large area and to share information over the internet.