Measurement of Carbon Monoxide (CO) Gas in Motor Vehicle Emissions Using ZE07-CO Sensor

Abstract

Air pollution caused by motor vehicle emissions has become a major environmental issue, particularly in urban areas. Carbon monoxide (CO), a toxic gas produced from incomplete combustion, poses serious health and environmental risks. This study aims to design and implement a portable CO emission monitoring system for motorcycles using the ZE07-CO electrochemical gas sensor integrated with an ESP32 microcontroller. The measured CO data are transmitted wirelessly via Bluetooth and visualized in real time through a Python-based Graphical User Interface (GUI) that also supports data logging in CSV format. Experimental results show that the CO concentration measured from a 4-stroke gasoline motorcycle engine ranged between 1.1 and 2.8 ppm, which is significantly below the national emission limit of 4.5% vol (≈45,000 ppm) as regulated by the Indonesian Ministry of Environment and Forestry. The system demonstrated stable performance with high sensitivity and accuracy, while maintaining reliable Bluetooth transmission up to 10 m without data loss. The developed prototype offers a low-cost and efficient alternative to conventional emission analyzers, making it suitable for educational use, small workshops, and on-site vehicle emission testing.