A number of approaches have been proposed recently for gases monitoring using WSNs.
The first approach involves the application of low power sensors implemented using chemical sensing films[4,5].
The sensor nodes employing the gas sensors of this kind are characterized by long term operation, but fail to meet the standard safety requirements [6] on early gas leak detection.
The second approach involves the application of power hungry spectroscopy based sensors [7] onboard of autonomous WSN devices.
These sensors can consume up to 500 mA, but are featured by high selectivity and fast response time that ensures safe and early hazardous gases detection
The employment of catalytic or semiconductor sensors is a viable trade-off between film and optical based approaches for gases detection using WSNs: they are more energy efficient than optical based solutions and, at the same time, have better response time, selectivity and sensitivity than film based solutions. In this work we use catalytic sensors.
Focusing on gas sensing [9,10] and communication of alert messages over the WSN to an operator [2], the problem of immediate actuation,
that is obviously an important action to prevent an
accidental situation, is not well investigated in the literature.
Closing a gas valve blocks the damaged boiler or a gas pipeline to prevent the leak of significant gas concentration while expecting the actuation command from an operator.
The goal of this paper is to demonstrate a wireless sensor–actuator system, which contains a wireless sensor node and wireless actuator that efficiently detect and react on gas leak in time.
The practical contribution of this work is twofold: