The Challenges of Prolonged Gas Sensing in the Modern Urban Environment

Abstract

The increase in the urban population is impacting the environment in several ways, including air pollution due to emissions from automobiles and industry. The reduction of air pollution requires reliable and detailed information regarding air pollution levels. Broad deployment of sensors can provide such information that, in turn, can be used for the establishment of mitigating and regulating acts. However, a prerequisite of such a deployment strategy is using highly durable sensors. The sensors must be able to operate for long periods of time under severe conditions such as high humidity, solar radiation, and dust. In recent years, there has been an ongoing effort to ruggedize sensors for industrial applications with an emphasis on elevated temperature, humidity, and pressure. Some of these developments are adapted for urban air sensing applications. However, protection from dust is based on filters that have not been modified in the last few decades. Such filters clog over time, thus requiring frequent replacement. This editorial presents the need for a consumable-free dust removal device that provides consistent performance without affecting the sensing process. A specific solution for removing dust using a cyclone dust separator is presented. The cyclone dust separator is implemented as an add-on module to protect commercially available sensors.

Optimal Wireless Distributed Sensor Network Design and Ad-Hoc Deployment in a Chemical Emergency Situation

“…Similarly, Somov et al developed sensors that can be deployed as WDSN within an industrial site [ 4 ]. However, operating WDSN in harsh environments reduces performance over time [ 5 ]. Hence, sensors must be protected [ 6 , 7 ] and undergo periodic maintenance [ 4 ].…”

Urban Air-Quality Estimation Using Visual Cues and a Deep Convolutional Neural Network in Bengaluru (Bangalore), India

“…Low-cost mobile sensors are often implemented to improve spatial resolution . However, such sensors must be calibrated periodically, especially for outdoor applications, and are subjected to harsh conditions. , Hence, despite the impressive progress in the research and development of miniature, low-cost sensors, their operation still involves an economic and technical burden, thus underscoring the need to develop methods and devices for chemical sensing that can exploit other signals such as visual cues from imagery data to complement sensory data.…”

Reconfigurable Modular Platform for Prolonged Sensing of Toxic Gases in Particle Polluted Environments

“…Continuous gas detection in the industrial environment has many technological challenges where the sensor is exposed to harsh conditions including solar radiation, temperature variations, humidity, and aerosols that may reduce sensor accuracy [5,[10][11][12]. The presence of particle pollution (aerosol) has a high impact on the sensor performance deterioration especially for prolonged sensing operation, even in locations deemed to be convenient.…”

“…Even though the size of the dust aerosol particles varies from place to place, a detailed study by Al-Attar et al showed that the particle pollution in Kuwait transported from the Arabian desert has a mean range of 3 to 6 µm [14]. Very few studies have explored technological solutions to minimize the undesirable effects of aerosol on gas sensors in the past few decades [10,15]. This paper addresses this gap by presenting a reconfigurable and modular platform for toxic gas detection that encompasses a microfluidic-filtration module.…”

“…However, higher energy is needed to draw air through the filter and the need for regular replacement of the filter. In addition, these filters could decrease the vapor concentration in the sampled air due to the adsorption of organic gas into the filter, resulting in low sensitivity and a long response time [10]. An alternative approach is to use a fluidic particle separator along the flow path.…”