Analysis of carbon monoxide in ambient air using passive sensors

Abstract

Air quality monitoring is necessary due to various pollutants that can have a harmful effect on human health. Carbon monoxide (CO) is a pollutant of concern because it is very toxic at low concentrations. It is an odorless and colorless gas that is very difficult to detect. In recent years, passive sensors have been widely used to analyze CO in ambient air. The CO sensor for commercial use must be stable during operation and have a linear and reproducible output over a long period. Hence, developing CO gas sensors with high sensitivity, selectivity, and stability is essential. This study compared three types of CO gas sensors: electrochemical, metal-oxide semiconductors, and colorimetric. Each of these sensors is characterized by specific advantages and disadvantages; therefore, their comparative analysis is presented, and their most important characteristics are emphasized.