Wireless sensor networks (WSN) have been adopted in various monitoring applications. However, due to the high power consumption of catalytic gas sensors, which enable reliable gas detection, there is a lack of real WSN deployments aimed at the monitoring of combustible gases. This work reports on the evaluation of a WSN deployed in a real operational boiler facility. The WSN consists of nine battery-powered wireless sensor nodes (with an onboard catalytic sensor) controlled by a network coordinator. In this safety critical environment our objective is twofold: (i) guarantee precise and fast sensor response, and (ii) deliver the sensed data from the sensor nodes to the network coordinator safely in case of methane leakage. We first describe the deployment of the WSN and then evaluate the catalytic sensor response under various conditions. Besides, we evaluate the wireless links using the received signal strength indicator (RSSI) and link quality indicator (LQI) metrics. Finally, the experimental results demonstrate that during 5 months of deployment the sensor nodes have been discharged for 22–27%.

/pdf/deployment-and-evaluation-of-a-wireless-sensor-network-for-4316yj33d5.pdf

Deployment and evaluation of a wireless sensor network for methane leak detection

Thousands of industrial gas leaks occur every year, with many leading to injuries, deaths, equipment damage, and a disastrous environmental effect. There have been many attempts at solving this problem, but with limited success. This paper proposes a wireless gas leak detection and localization solution. With a monitoring network of 20 wireless devices covering $200\;\text{m}^2$ , 60 propane releases are performed. The detection and localization algorithms proposed here are applied to the collected concentration data, and the methodology is evaluated. A detection rate of 91% is achieved, with seven false alarms recorded over 3 days, and an average detection delay of 108 s. The localization results show an accuracy of 5 m. Recommendations for future explosive gas sensor design are then presented.

Wireless Gas Leak Detection and Localization

Wireless sensor network (WSN) is one of the interesting issues in the information technology domain. It is used in various fields such as medicine, agriculture, meteorology, etc. that eases lots of difficult tasks to do but have some challenges too. Deployment is the greatest challenge in WSN that affects other features like coverage, connectivity, energy efficient and lifetime. Despite the importance of the deployment problem in WSN, to the best of our knowledge, there isn't any systematic literature review to give us systematical analyses the state-of-the mechanisms in this field. Therefore, this study reviewed the deployment mechanisms which have been used in WSN systematically. The deployment mechanisms can be classified into two main categories: deterministic and nondeterministic. Also, this study represents a comparison of the important techniques of the selected articles in each category to offer a guideline for further studies and new challenges. We also have noted some open issues for future research.

Deployment Strategies in the Wireless Sensor Networks: Systematic Literature Review, Classification, and Current Trends

Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on objects, networked by short-range wireless links, allowing the physical parameters such as temperatures and humidities as well as the location information to seamlessly integrate with the enterprise information system over the Internet. In this paper, challenges, considerations and design examples are reviewed from system, implementation and application perspectives, particularly with focus on intelligent packaging and logistics for the fresh food tracking and monitoring service. An IoT platform with a two-layer network architecture is introduced consisting of an asymmetric tag-reader link (RFID layer) and an ad-hoc link between readers (WSN layer), which are further connected to the Internet via cellular or Wi-Fi. Then, we provide insights into the enabling technology of RFID with sensing capabilities. Passive, semi-passive and active RFID solutions are discussed. In particular, we describe ultra-wideband radio RFID which has been considered as one of the most promising techniques for ultra-low-power and low-cost wireless sensing. Finally, an example is provided in the form of an application in fresh food tracking services and corresponding field testing results.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2013.0313

Radio frequency identification enabled wireless sensing for intelligent food logistics.

We present a suspended carbon nanotube gas sensor that senses NO2 at ambient temperature and recovers from gas exposure at an extremely low power of 29 μW by exploiting the self-heating effect for accelerated gas desorption The recovery time of 10 min is two orders of magnitude faster than non-heated recovery at ambient temperature This overcomes an important bottleneck for the practical application of carbon nanotube gas sensors Furthermore, the method is easy to implement in sensor systems and requires no additional components, paving the way for ultra-low power, compact, and highly sensitive gas sensors

Ultra-low power operation of self-heated, suspended carbon nanotube gas sensors

Wireless Sensor Networks (WSN) have recently been applied in various monitoring applications including hazardous gases detection. However, being a major power consumer of a sensor node, off-the-shelf gas sensors significantly constrain its lifetime. In this paper we present a WSN for hazardous gases detection with a special focus on the power consumption of the sensor node. The sensor node is designed on the basis of a planar catalytic sensor with improved power consumption characteristics. The power supply of the node is divided into digital and analogue parts. This is done to guarantee digital remote control of the device even when the analogue power source has already been depleted by the sensing circuit. In addition, we propose a differential gas measurement approach along with specific heating pulses for the sensor to secure substantial energy saving. The resulting average power consumption is 1.45 and 2.64 mW for the gas sensor and the sensor node respectively. With our techniques, the sensor node lifetime improves from 187 days up to 641 days.

/pdf/energy-aware-gas-sensing-using-wireless-sensor-networks-3lhkgufja6.pdf

Energy-Aware gas sensing using wireless sensor networks

Wireless sensor networks (WSNs) have recently been applied for industrial monitoring, including combustible and flammable gases monitoring. In this work, we present a wireless gas sensor node in which a widely used Wheatstone sensing circuit based on two sensors is exchanged with a single sensor circuit, as well as the associate gas measurement procedure. The core of the measurement procedure is the four-stage heating profile, which enables low power consumption of sensing circuit and thermo compensation adjustment. A thermo compensation algorithm is capable of avoiding the effect of the environmental temperature on the measurements by keeping stable zero-offset within $\pm 1\;\hbox{mV}$ and ensuring low absolute error within 0.1% vol. The thorough design of the sensor node allows it to fit into the $5.5\;{\hbox{cm}^3}$ packaging, which ensures its true ubiquitous deployment in outdoor and industrial environment.

/pdf/compact-low-power-wireless-gas-sensor-node-with-thermo-3q1c3esgm0.pdf

Compact Low Power Wireless Gas Sensor Node With Thermo Compensation for Ubiquitous Deployment

The design and main technical characteristics of a typical catalytic sensor are described. The main drawbacks related to the lack of stability due to natural ageing and poisoning of sensing elements by catalytic poisons are defined. It is suggested to provide a restricted access of the analyzed gas mixture into the reaction chamber by diffusion through a calibrated hole to increase the stability of sensor.

Increase of catalytic sensors stability

A huge number of combustible gas leaks occur every year at industrial and home facilities. These leaks may have grave consequences for health, environment and property. In this work we demonstrate the approach for improving the interoperability of catalytic sensors which are widely used in industrial monitoring applications for combustible gas leaks. To ensure methane detection within the broad concentration range (100 ppm–100% vol.), we propose using of two sensors with catalysts in the modified Wheatstone sensing circuit and to cover them with sealed caps with different holes to enable gas diffusion control.

/pdf/improving-interoperability-of-catalytic-sensors-4n29oy30pa.pdf

Alexey Suchkov

Papers

Energy-Aware gas sensing using wireless sensor networks

Compact Low Power Wireless Gas Sensor Node With Thermo Compensation for Ubiquitous Deployment

Increase of catalytic sensors stability

Improving interoperability of catalytic sensors