GAS SENSING PROPERTIES OF ALKALI AND RARE EARTH ELEMENTS DOPED TIN DIOXIDE

Abstract

newline A sensor is a device that can receive and respond to a signal or stimulus. The stimulus/measurand can be the quantity, property, or condition that is sensed and converted into electrical signal. The purpose of a sensor is to respond to some kind of an input (physical or chemical property) and convert it into electrical signal that is compatible with the electronic circuits. Sensor is a device that responds to a physical (or chemical) stimulus (such as heat, light, sound, pressure etc.) and transmits a resulting impulse (for measurement or operating a control) [1, 2]. Thus sensor can detect an input signal and convert it into an appropriate output signal. Generally, sensors provide an interface between the electronic equipments and the physical world typically by converting nonelectrical, physical or chemical quantities into electrical signals. Nowadays, due to the increase in the environmental pollution, and industrialization sensors have attracted a great deal of interest in environmental monitoring and various industries to improve environmental and safety control of toxic and inflammable gases. There is an urgent need to develop the gas sensors which have several applications in automotive and industrial manufacturing, medical diagnostics and health care, defence and security, detection of harmful gases in mines, grading of agro-products like coffee and spices, in packaging quality control, in weather stations, etc. [3-7].