Joshua Suresh#1, Gauri Vaidya*2, Tushar Thote#3
#1, 2, 3 Students, Dept. of Electronics and Telecommunication,
St. Vincent Pallotti College of Engineering & Technology, India
Gaseous Substance in Atmosphere like COx, SOx, NOx quality monitoring is extremely important in today’s world as it has direct and indirect marked influence on living being. These gas substance is on rapid rise due to various environmental pollution activities made by human being and its monitoring is of vital importance to take certain measure to control it. In this project we put forward a low-cost and low-power system for gas substance quality monitoring.
This system is in contrast to stationary air pollution monitoring stations as we present the design, implementation and working, a small and portable monitoring system that is based on low-cost sensors and microcontroller and can be commercially used by a numbers of people.
The data from the sensors on monitoring system can be collected from various places and be stored, analyzed, plotted graphically and easily updated on dedicated webpage. Vital to the success of sensing application is the high quality data from the sensors. The data collected by the sensors on microcontroller is then plotted in real-time on a computer and can be stored.
Furthermore, a temperature and humidity is included as these conditions can impact the performance of the gas sensors. Finally, we compare the data from monitoring system of a region with the data of ‘Nagpur Central Pollution Board’, Civil Lines, Nagpur.
Index Terms — Arduino, Gas Sensor, Gaseous Substance monitoring, Real-time data plotting, Serial communication and Interfacing.
Gaseous pollutant such Cox, NOx, Sox have a direct and indirect impact on the human health; they are responsible for a variety of respiratory illness and can cause cancer in humans if they are exposed to these pollutants for extended periods of time.
Recently Cox, specifically Carbon monoxide is highly toxic to humans as it can cause severe headaches due to formation of carbon-xy-hemoglobin and even death if exposed for prolonged time. Also this harmful Cox, Sox & NOx are responsible for many environmental problems such as ozone layer depletion and acid rain. Hence, Gaseous substance monitoring is vital now a day in urban and industrial areas.
Gaseous substance monitoring by Electrochemical monitoring stations: Electrochemical gas detector work by allowing gases to diffuse through a porous membrane to an electrode where it is either chemically oxidized or reduced.
The amount of current produced is determined by how much of the gas is oxidized at the electrode, indicating the concentration of the gas. In this chemical is taken to laboratory and manual tested by official authorizes However, the sensor is subject to corrosive element or chemical contamination and may last only 1-2 years before a replacement is required.
Gaseous substance monitoring by Semiconductor sensor: Semiconductor sensor detect gases by a chemical reaction that takes place when comes in direct contact with the sensor. Tin oxide is the most common material used in semiconductor sensors, and the electrical resistance in the sensor is decreased when it comes in contact with the monitored gas. This change in resistance is used to calculate the gas concentration.
Since the air pollution monitoring station are costly and so are limited in number in urban areas, we have come up with this system which is small and portable measurement system which includes various gas sensors and microcontroller that can be used by large number of people.
Thus this system provides the user with:
- Low-cost and low -power measurement hardware that is suitable for mobile measurement;
- User-friendly data collection and processing database;
- Gathering high quality data;
- Easy to use instrument that can be used commercially by a large number of people.
We connect small sized, low cost sensor to an Arduino Uno microcontroller module which is then connected to a computer via serial communication. The data collected by the Arduino microcontroller from the sensor will then be sent to the dedicated webpage where it is kept recorded. This sensor based system can be used easily by a large number of people and would thus contribute to monitoring gaseous quality in the society.
II. System Design
This section short describes the hardware components and block diagram of Gaseous substance in atmosphere monitoring:
Our measurement system consists of three parts.
- We use semiconductor sensor module to sense the gas substance concentration in the atmosphere making use of the measured resistance of the sensor and temperature and humidity are also included as these condition effect the performance of the gas sensing.
- The Arduino Uno board is connected to the semiconductor gas sensor module and
- Connected with GSM module for data logging and sending text message. All the Parts of the system are easily available at low prices. This is essential to obtain widespread acceptance of the air pollution monitoring system.
2.1.1 MQ series (Gas Sensor):
This is a simple-to-use semiconductor sensor, suitable for sensing gas substance concentration in the air. This sensor has a high sensitivity and fast response time. The sensor’s output is as analog resistance. Thee drive is very simple; it need to power the heater coil with 5V, add a load resistance and connect the output to an analog to digital convertor. The sensitivity of the sensor can be adjusted by using the potentiometer.
2.1.2 Temperature and humidity sensor:
The DHT 11 sensor are made of two parts, a capacitive humidity sensor and thermistor. There is also basic chip inside that does some analog to digital conversion and splits out a digital signal with the temperature and humidity. The digital signal is fairly easy to read using Arduino.
2.2.2 Arduino Uno:
It is microcontroller board based on the ATmega328. The boards are equipped with sets of digital and analog input/output pins that may be interfaced to various expansion boards (shield) and other circuits. The board feature serial communication interfaces.
2.1.4 GSM module:
GSM is a class of wireless MODEM devices that are designed for communication of a Arduino with the GSM network. It requires a SIM card just like mobile phones to activate communication with the network. Also they have IMEI (International Mobile Equipment Identity) number similar to mobile phones for their identification.
III. Knowledge Gained
MQ Series: The MQ series module has 4 pins, two are to fetch signals and other two used for providing heating current standard measuring circuit. One is heating circuit having time control function. The second is the signal output circuit, it can accurately respond changes of surface resistance of the sensor.
The surface resistance of the sensor Rs is obtained through effected voltage signal of the load resistance RL which series-wound. The relationship between them is described:
Rs/RL = (Vc-VRL) / VRL sensitive layer of gas sensor sensitive components is made of SnO2 with stability. Thus it has excellent long term life duration with certain condition. In the above some mind blowing algorithm are used for calculating different gaseous substance from different sensor and calibrating it accordingly. Time and Date Extraction from GSM Module in real-time using Arduino and uploading accordingly: Time and date is major issue for uploading in data base system, because in GSM we have check it continually according to gas substance variation and in dangerous situation for sending message.
The major factor was power management and program code management because of many devices connected to Arduino and getting signal data using serial communication.
Initially idea was intended to provide the user with cost-effective means of determining air quality. Sensor focus was on the Cox, NOx and SOx.
As in the future we can also add a calling feature to know the value of the gases present in air at that time with temperature and humidity on the message, whenever a call is accomplished and follow instructions. More gases can also be detected with add up of different sensors and little advancement in the program will required.
- https://www.google.co.in/search?q=types+of+gas+ sensors&oq=types+of+gas+sensors&aqs=chrome..69i57j0l5.4987j0j7&sourceid=chrome&ie=UTF-8