Design of IoT-based Volatile Organic Compounds Monitoring System

Abstract

Volatile organic compounds (VOC) gas detection devices based on semiconductor sensors have become a common method due to their low cost, simple principle, and small size. However, with the continuous development of materials science, various new materials have been applied in the fabrication of gas sensors, but these new materials have more stringent requirements for operating temperature, which cannot be met by existing sensor modules on the market. Therefore, this paper proposes a temperature-adjustable sensor module and designs an environmental monitoring system based on the STM32F103RET6 microprocessor. This system primarily utilizes multiple semiconductor gas sensors to monitor and record the concentrations of various harmful gases in different environments. It can also monitor real-time temperature, humidity, and latitude and longitude in the current environment, and upload the data to the Internet of Things via 4G communication. This system has the advantages of small size, portability, and low cost. Experimental results show that the sensor module can achieve precise control of operating temperature to a certain extent, with an average temperature error of approximately 3%. The monitoring system demonstrates a certain level of accuracy in detecting target gases and can promptly upload the data to a cloud platform for storage and processing. A comparison with professional testing equipment shows that the sensitivity curves of each sensor exhibit similarity. This study provides engineering and technical references for the application of VOC gas sensors.