Babu K. Senthil, Nagaraja .C, International Journal of Advance Research, Ideas and Innovations in Technology. © 2018, www.IJARIIT.com All Rights Reserved Page | 18 ISSN: 2454-132X Impact factor: 4.295 (Volume 4, Issue 1) Available online at www.ijariit.com Calibration of MQ-7 and Detection of Hazardous Carbon Mono- oxide Concentration in Test Canister K. Senthil Babu Department of Electronics S K University, Anantapur, Andhra Pradesh ksenthilbabu80@gmail.com Dr. C. Nagaraja Department of Electronics S K University, Anantapur, Andhra Pradesh c_nagaraja@yahoo.co.uk Abstract: The most active research in recent years is estimating the noxious waste which has a very high influence on the human health. There are many gases which have adverse effects on human health. Here carbon monoxide (CO) is considered as one of toxic gas which is considered to cause various health issues based on the concentration the casualty is exposed. In this paper, we ensure the presence of hazardous gases and also provide the procedure to estimate the concentration of the same with the help of the MQ-7 sensor and test setup. The calibration of the sensor is carried out with a canister of known volume and the estimation of the CO in the test environment is also determined. Keywords: Calibration; MQ-7; Hazardous Gases. I. INTRODUCTION Many circumstances [3], test experiments lead to the production of gases and vapours directly or indirectly. These gases and vapours are classified in to different levels of hazardousness and toxicity [10] [11]. Those hazardous and toxic gases when inhaled or exposed to humans have harmful effects. There are gases that become dangerous to health in concentrations as little as 1ppm (parts per million). Workers are at high risks to these gases which causes various health aliments depending on the duration of the gases they are exposed too. Hydrogen sulphide has a bad odour at 0.1ppm but leads to paralysis when exposed to the concentration over 50ppm. This does not strictly suggest that 50ppm is the hazardous limit but even if the concentration is slightly below than the hazardous level may lead to paralysis or death when exposed to longer durations. Various other gases like Ammonia, carbon dioxide, carbon monoxide, Methane have their own characteristics. Ammonia has a threshold limit of 25ppm whereas 500 ppm is immediately dangerous to life. Carbon dioxide produced by combustion, fermentation, brewing methods has a maximum safe level of 5000ppm beyond which may cause severity in health issues. Carbon monoxide (CO) is a class-III toxic gas which is slightly less dense than air and it is a colourless gas with neutral odour and also tasteless. This gas can readily mix with air and can be readily inhaled. There are many cases of carbon monoxide poisoning reported in many countries [5]. The threshold limit is 25ppm and when the concentration is 1200ppm and greater leads to a very high risk for life. In this paper, we determine the concentration of the carbon monoxide gas in the test environment and also calibrate the sensor to read the amount of CO present in the canister. Calibration is the process of configuring an instrument to provide a result for a sample within an acceptable range [6] [7]. The accuracy of the instrument is maintained or altered according to requirements by calibrating the instrument. The main operation of calibrating [8] [9] the device is to eradicate and minimize the factors that cause imprecise measurements. The procedure for calibrating devices may vary but generally, it involves using the instrument to test samples for various values. These values from the test samples are called as "calibrators". Calibrations are performed using calibrators to establish a complement at specific points within the instrument’s operating range. On a practical aspect, a settlement must be made between the desired level of product performance and the effort correlated to conclude the calibration.