Review of studies on sensor networks for CO2 monitoring

<p>Currently, in metropolitan areas, the amounts of polluting gases are increasing, which causes the growth of global warming. One of the leading gases causing the greenhouse effect is carbon dioxide (CO2). For this reason, its monitoring and control is a highly studied topic worldwide due to the various problems in the ecosystem. One of the ways to monitor CO2 levels in the environment is through devices with specialised sensors and wireless communication through a sensor network. This research paper presents a bibliographic review of studies on sensor networks for CO2 monitoring. The objective of this article is to identify which are the sensors and the most used communication technology for the monitoring of this polluting gas. The methodology used in this article is a bibliographic review, which effectively allows the investigation of information to perform a critical analysis. Scientific articles, doctoral thesis, and other research on this subject have been considered for analysis. The results concluded that the most widely used wireless protocol is Zigbee due to its reduced energy consumption in implementation. The MQ-135 sensor is the most used, which is indicated to detect harmful gases in a maximum range of 10-1000 ppm (parts per million).</p&gt