Authors : D. Thakur*,M. Jha**,B. Sharma***
Page Nos : 1278-1285
Description :
Semiconducting metal oxide sensors are one of the most widely studied technique of gas sensing. These sensors are designed to react with a class of gases by reduction and oxidation. This process causes the semiconductor oxide sensors to exchange electrons with the target molecule of gas at a certain characteristic rate, and in this way affects the sensor’s resistance and generate a certain signal. The reaction of semiconductor oxide materials with gases and the result of the conductometric changes were introduced in 1950\\\'s by Brattein et al. and Heiland. After that Bielanski et al . and Seiyama et al. introduced applications of the semiconductor oxide sensors as catalysts and electric conductive detectors toward various gases . During few years past semiconductor oxide gas sensors is becoming a prime technology in the detection of pollutants with very low concentration in river, pond, reservoir, lake and municipal supply water.
There may be three types of sensors available which are based on electrochemical nature, catalytic combustion and resistance modulation of semiconductor oxides with metals.
Semiconductor oxide gas sensing devices have several unique advantages such as low cost, small size, measurement simplicity, durability, easy fabrication, and low concentration detection. To enhance the accuracy of these sensors we use some materials. These Semiconductor oxides mixed with different dopants, catalysts, adhesives, binders, volatile fillers, and electrodes. To mix we uses different deposition techniques like pyrolysis, oxidation of metallic films, reactive sputtering, chemical vapor deposition (CVD), laser ablation, and electron-beam evaporation techniques. Here we are using this gas sensing technology for detecting the pollutants (NH3 & Amine) in the
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atmosphere of Gwalior’s industrial area and atmosphere of nearby area of swarnrekha river drainage.
