Rostislav Varzar

Faculty of Computers and Information Science
Speciality: Computer Monitoring Systems

Theme of master's work:

Development of automatic system monitoring air pollution

Scientific adviser: professor, D.T.S. Gennadiy Averin

Introduction

Donetsk region is one of the most populated, economically potential and richest in natural resources area of Ukraine. It has one fifth of the industrial potential of the state. It has about 1.5 thousand major industrial enterprises of the key country industries: mining, metallurgical, chemical, machine-building, power and building.

Most of the major industrial enterprises of the region are ecologically dangerous objects. According to the data of the State statistics committee Donetsk region has 34% of the general amount of pollution from stationary sources. General amount of emission of harmful substances in 2007 made 1654 thousand tons [1].

The conclusion we can draw from the current situation is that in Donetsk region it is necessary to create the automatic system of ecological monitoring allowing not only to watch but also to predict the levels of atmosphere pollution.

Aims and tasks

The aim of my master’s degree work is to develop the automated system of atmosphere pollution monitoring, which allows to carry out automatic control of air condition on the local level, show and present information with the help of Web-technologies.

The tasks of my master’s degree work:

• analysis if the current methods to measure low concentrations of harmful substances in the atmosphere, methods of automatic data collection and types of the sensors used;
• formation of the requirements to automated monitoring system;
• development of principal schemes and construction of the automated gas-analyzer as a measurement unit of an automated system;
• development of the automated system software;
• combination of technical means, usage and testing of an experimental model of the gas analyzer and automatic monitoring system.

The supposed scientific novelty is in the following:

• overview of methods of analysis of harmful substances low concentration in the atmosphere, such as atomic emission spectroscopy;
• development of a similar automated monitoring system is a totally new achievement in our country and for our region;
• the system itself is completely automated, carries out constant control of the atmosphere condition and the system’s data are available to anyone.

Approbation

The results of the research on automatic data collection from remote sensors were reported at the international conference “Computer monitoring and information technologies” (KMIT-2009). The topic of the report was “Development and application of wireless communication systems for measurement of the atmosphere parameters”.

The summary of the results

The automated monitoring system of the air pollution includes the following components:

1. Automatic post of atmosphere pollution including:
   
• gas analyzer;
• weather station;
• computer;
• communication means;
2. Remote Web-server.

There may be unlimited number of automatic posts. To connect with Web-server standard types of the Internet connections are used (fig.1).

The main measurement device of the automated system is the gas analyzer. It is an important component, because the gas analyzer determines the concentration of harmful substances in the atmosphere.

The main requirements to the gas analyzer are:

1. Determination of low concentrations of contaminating substances
2. High accuracy of measurements
3. The number of determined substances is at least 3 – 5
4. Possibility of continuous operation for a long time
5. Reliability of gas analyzer sensors
6. Average life time of sensors before their replacement – at least 1 year
7. Low time drift of analyzer registration
8. Compact size
9. Low power use
10. Wide range of atmospheric conditions in which the gas analyzer can be used
11. There must be the elements produced in lots
12. Low cost of the gas analyzer

Before the beginning of gas analyzer development there were analyzed 3 most common methods of analysis of air substances contents:

1. Electrochemical
2. Chemiluminescent
3. Atomic emission spectroscopy

The choice of method of analysis of harmful substances contents in the air

Every of the above mentioned methods has its advantages and disadvantages. For example, in chemiluminescent sensors substrate with the composition solution must be changed once in two days or in 2 weeks (depends on the analyzed substance). For constant control without a man it is not suitable. Atomic emission spectroscopy presupposes either very bulky devices, or compact, but extremely expensive and complicated equipment.

That’s why to develop a gas analyzer electrochemical sensors were chosen. The used sensors are produced in lots by a Swiss company Membrapor [2]. The main sensors characteristics are given in table 1.

• Temperature range: -20…+50ºC
• Relative humidity range: 15…90%
• Life time of sensors: 2 years

Based on technical characteristics of sensors provided by the producer it is possible to conclude that these sensors are quite acceptable for a gas analyzer development. Moreover the sensors producer carries out sensors control and gives a corresponding certificate.

Gas analyzer development

Construction of the gas analyzer consists of two technical systems – electronic and air-gas.

Figure 2 presents a structural flow chart of the gas analyzer electronic system.

Figure 3 presents the structural flow-chart of the air-gas system.

The first experimental model of a gas analyzer is called AIRHACKER-1.

The gas analyzer is a device for measuring nitrogen dioxide, hydrogen sulphide, formaldehyde, ammonia and ozone concentration in the air. It displays the data on an LCD and transmits the data through the serial port (RS-232, RS-485 or USB) into the computer.

Main technical characteristics:

• range of measured concentrations of nitrogen dioxide NO₂: 0–20 ppm (0–37 ìã/ì³);
• range of measured concentrations of formaldehyde CH₂O: 0–10 ppm (0–12 ìã/ì³);
• range of measured concentrations of hydrogen sulphide H₂S: 0–50 ppm (0–71 ìã/ì³);
• range of measured concentrations of ammonia NH₃: 0–100 ppm (0–71 ìã/ì³);
• range of measured concentrations of ozone O₃: 0–5 ppm (0–10 ìã/ì³);
• accuracy of nitrogen dioxide NO₂ concentration measurement: 0.1 ppm (0.18 ìã/ì³);
• accuracy of formaldehyde CH₂O concentration measurement: 0.01 ppm (0.012 ìã/ì³);
• accuracy of hydrogen sulphide H₂S concentration measurement: 0.05 ppm (0.071 ìã/ì³);
• accuracy of ammonia NH₃ concentration measurement: 1 ppm (0.71 ìã/ì³);
• accuracy of ozone O₃ concentration measurement: 0.03 ppm (0.06 ìã/ì³).

Conditions of operation:

• range of working temperatures: –10…+40ºC;
• relative humidity: 0…80%, non-condensed;
• atmosphere pressure: ±10% from normal atmospheric.

Electrical characteristics:

• supply voltage: 220 V (mains, 50 Hz) / 12 V (battery);
• power consumption: 30 W.

Physical specifications:

• dimensions: 300 x 100 x 100 mm;
• mass: 2 kg.

Software of automatic post

At present the software which reads data from industrially produced gas analyzers CM-NO2-SO2-CO and weather stations DAVIS Vantage PRO is being tested [3]. The program to control the gas analyzer is written in the programming language Borland Delphi 7.0. It includes several modules:

• module of initialization and reading data from port RS-232;
• module of information development, data averaging and normalization;
• module of exchanging data with Web-server.

Figure 4 presents a screen-shot of the program for reading data from gas analyzer and weather station.

Remote Web-server

Remote Web-server consists of 2 components:

1. hardware subsystem;
2. upper level software.

Hardware subsystem is a computer connected to the internet via modem or any other device. It does not matter where in fact hardware of the Web-server is situated. It can be either any computer at university or a server of internet-provider in the USA. The important thing is that it must have access from outside via the Internet.

Upper level software is a component of the software of automated monitoring system and its structure and algorithms are determined by tasks and functions of the processing system, storing and keeping information.

Upper level software operation is provided by the following software components:

• OS Microsoft Windows XP;
• system of relational data bases control MySQL;
• server Apache;
• programming language PHP;
• programming code of automated system.

Upper level software provides processing, storing and presenting of information. To fulfill this function the following software functions are defined:

• continuous data reading;
• entrance, transformation, storage, presentation and processing of information, received from control means and stored in relational database;
• formation and provision of data;
• printing reports and summaries;
• carrying out calculations and informational tasks of the complex;
• organization of databases backup;
• organization of informational exchange between the complex and remote users via the internet;
• organization of interface with the complex operator;
• visualization of information as graphs;
• organization of backup copies of databases;
• protection of information from unauthorized access.

Realization of these functions will allow to fulfill the task of processing, storage and presenting of information.

At present the resource ÀÊÈÀÌ is used, which was specially designed to combine automated data collecting posts. It also presupposes manual data setting [4]. Figure 5 shows the table of current measurements, constantly updated by automated post ¹6.

Planed practical results

Realization of the following stages is planned in future:

• launch of automated monitoring system to collect data on atmosphere pollution;
• analysis of the received data and prognosis of possible changes;
• small-lot production of automated posts.

Conclusion

Analysis of the data and current data collecting, storing and processing systems in Donetsk allows to characterize the working systems of ecological monitoring as not conforming to modern conditions and requirements.

In this connection analysis of the information allows to conclude the following:

• now marketed automated systems of ecological monitoring are extremely expensive;
• foreign automated systems of ecological monitoring have quite developed hardware component but very limited software. In cases with imported systems it will be necessary to have additional expenses on adaptation of the basic software and development of modern analytical software;
• devices used in most automated monitoring systems were not certified in Ukraine;
• in most cases development of these systems did not take into account norms of normative-methodological documentation in the sphere of ecological monitoring of the atmosphere.
• implementation of foreign systems needs big capital investments and consequent annual operating costs, which is hardly possible in the present economic situation.

That is why it is necessary to design a new automated system of the atmosphere pollution monitoring suitable for Ukrainian market, which is cheap and reliable, able to carry out continuous automatic control for at least 2 years.

Literature

1. Programs of economic and social development of Donetsk. Donetsk city council, 2000…2008.
2. Membrapor. Product range. [Electronic resource] : http://www.membrapor.ch/products.htm
3. DAVIS. Vantage Pro2. [Electronic resource] : http://www.davisnet.com/weather/products/vantage2.asp
4. Hardware and software complex of ecological monitoring of atmospheric air ÀÊÈÀÌ. [Electronic resource] : http://www.akiam.org.ua/

Commentary

The master’s work was not completed yet while writing this abstract of thesis. The date of completing is 1 December, 2009. The full text of the work and the material on this subject can be received from the author or its curator after the given date.