Study On The Online Monitoring System Of Volatile Organic Gases Based On NB-IoT

Since the reform and opening up,China has continuously strengthened the construction of industry,manufacturing and urbanization.The per capita disposable income has been increasing,and the number of private cars has been increasing.However,the pollution of the atmosphere to the atmosphere has been neglected,resulting in more serious air pollution problems.The pollutants are mainly composed of fine particles and ozone.The prerequisite for the formation of these two is Volatile Organic Compound(VOC).In recent years,China has promulgated a series of related policies on issues such as atmospheric pollution,among which VOC has always been the main target of control and governance.In order to respond to the call of the state,strengthen the construction of ecological civilization.This paper introduces the NB-IoT based VOC online monitoring system,which consists of VOC monitor,NB-IoT transmission module and transparent cloud platform.The VOC monitor can perform on-line monitoring of the VOC gas in the tested area,and has the functions of real-time display and remote transmission of VOC gas concentration values.The user can view the concentration of VOC gas in the measured area on the monitoring platform.The photoionization gas sensor used in the monitor has the characteristics of small volume,small mass,high sensitivity,fast detection speed,etc.,and does not destroy the gas component to facilitate gas recovery.The VOC monitor adopts STM32F407 as the core main control chip,and designs the corresponding clock circuit,power supply circuit and analog-to-digital conversion circuit,etc.,and transplants the compact and easy-to-cut FreeRTOS real-time operating system to the main control chip to enhance the real-time performance of VOC monitor.The VOC monitor uses a cellular-based Narrow Band Internet of Things(NB-IoT)technology to enable remote data transmission.The system selects the NB-IoT module that supports the telecom operator.This module can process the received serial port data and send it to the remote server for remote transmission of data.After testing and analysis,the system has realized the real-time online monitoring of VOC gas in the monitored area.