Description of constant monitoring telemeter system

Environmental Environmental Pollution Monitoring Center measures 24 hours a day atmospheric environment at elementary and junior high schools and ward offices, as well as the status of pollutants emitted from large-scale plants.
These measurement data are monitored using a constant monitoring telemeter system.
This page provides an overview of the constant monitoring telemeter system in Yokohama City, the equipment used, and the concept of system design.

The system diagram of the constant monitoring telemeter system is shown below.
This system consists of a "measurement station data collection system" that collects measurement data from a measuring station, and a "control, monitoring, analysis, and reporting output system" that outputs the control and measurement data of the measuring station.
The "measurement station data collection system" consists of slave station equipment, central station equipment, recorder, etc. installed at measurement stations around the city, and stores the measurement data collected by slave station equipment in a database.
The "Control / Monitoring / Analysis / Report Output System" grasps and controls the operation status of measuring machines, etc., computerizes measurement data collected from various parts of the city, and outputs forms.
The current status of atmospheric environment is announced on the homepage of Motoichi and the homepage of Kanagawa Prefecture.

Constant measurement of the general atmospheric environment is carried out by the General Environmental Atmospheric Measurement Station (20 stations) installed in residential areas in the city and the automobile exhaust gas measurement station (8 stations) installed along arterial roads. Measure the concentration of substances.
At the same time, weather data such as wind direction and wind speed are also measured at the same time to understand fluctuations in environmental concentrations.

The constant monitoring of atmospheric sources covers large-scale fixed sources (30 factories in the city). The target factories measure fuel consumption and the concentration of nitrogen oxides and sulfur oxides in flue are measured.

The connection diagram of the slave station is shown below.

The slave station equipment installed at the general atmospheric environment, atmospheric source, and water quality source measurement stations installed in various parts of the city are measured from measuring machines (sulfur oxides, oxidants, etc.) installed at the measuring station. Etc. However, in the case of a source measurement station, the measurement value data provided by the operator is obtained. This data acquisition is performed automatically (per minute) and is transmitted to the central station equipment in response to the data request signal from the central station. If the measuring instrument installed in the measuring station is a digital measuring machine, the slave station equipment obtains data directly from the digital measuring machine via TCP/IP communication using Ethernet. If the measuring instrument is an analog measuring machine, the slave station unit acquires the data of the analog measuring instrument via a digital converter (a device that converts analog values into a digital signal) via TCP/IP communication. In particular, in the case of a water quality source measurement station, the slave station equipment acquires data from the load calculationr via TCP/IP communication using Ethernet.

Measurement data, measurement device status signals, etc. are transmitted and received between the slave station equipment and central station equipment using TCP/IP. In addition, it also has a function to communicate with local workers via IP phone during maintenance and inspection of measuring machines and measuring stations.

The central station system transmits a data request signal to the whole child station equipment for every minute, and each slave unit transmits the measurement data to the requested signal. Central station equipment automatically recollects data if data reception fails for any reason. As a result, data from all stations and all items are collected at once, and the collected data is stored in a database. At this time, recollection automatically performs scheduling so that it does not interfere with regular collection. In the case of atmospheric environment, atmospheric sources, and water quality environment measurement stations, the central station equipment calculates the estimated and confirmed one-hour values.

For secondary operations, the emission, load, etc. are calculated using the hourly value (primary data) stored in the database by the central station unit, and the calculation results are stored in the database again.

The operating table software always displays information about the operation of the constant monitoring system, such as the operating status of the measuring machine at each measuring station, whether or not there is a call request from each measuring station, and the communication status between the devices.

The central station outputs atmospheric environmental data to a recorder in real time to centrally monitor air pollutants such as photochemical smog, nitrogen oxides, and fine particulate matter.

The control and monitoring server compiles the measurement data collected by the central station equipment and creates time signals, daily reports, etc. In addition, we will issue and release photochemical oxidant warning, monitor microparticulate matter (PM2.5), disseminate high concentration information to citizens, and monitor the current source factory.

Based on the measurement data calculated and stored by the central station equipment and the secondary operation server, the analysis and report output server performs aggregation work such as daily, monthly report, annual report, annual report, etc., report output based on various report formats, and corrects stored measurement data. If this data modification changes the fixed 1 hour value or secondary calculation result, it will be automatically recalculated.
The user interface has web-based data browsing, modifying, and analyzing pages, and can be accessed from PCs and other devices on the same network. Since all report outputs are performed in sequentially computed, no intermediate data is stored on the system. The output results using the latest data can be obtained at all times.

Database software running on database servers is required to comply with standard SQL. It manages the measurement data stored in the database and provides interfaces for references and data modifications from the control and monitoring servers and analysis/reporting output servers. In addition, in order to be able to easily respond to future utilization of big data and publicity to citizens, it is necessary that the data output function and data interface be highly scalable.