Design and performance analysis of controllers for liquid level regulatory systems

Abstract

Monitoring and control of liquids, fluids, semisolids, molten metals, newlinechemicals and water is an important industrial exercise that directly affects newlinethe quality of the product being manufactured. It is necessary to maintain newlinepredefined levels of liquids and for this purpose, certain methodologies and newlinetechniques are followed. newlineThe monitoring and control of the liquid level has important steps newlineand the first among them is the measurement of the liquid level. Depending newlineupon the physical and chemical characteristics of the liquid different level newlinesensing systems are used. newlineInvasive and non-invasive level detectors are being used in the newlineindustries. The invasive types of level sensors are immersed in the fluid for newlinewhich the level is to be monitored. For example, the float type level sensor is newlinepartially invasive and the electrode types of level sensors are in direct contact newlinewith the liquid and are mounted within the tank or container. newlineNon-invasive type of sensors are mounted externally and are not in newlinedirect contact with the liquid but certain indirect methods based on ultrasonic, newlineand optics are used. The laser type level sensors, the visible light based level newlinesensors and the infrared light based level sensors are optical sensors. The newlineultra-sonic level sensors are sound based. All these sensors are non-invasive newlineand they do not come in direct contact with the liquid. Depending upon the newlinechemical and physical nature of the fluid including the temperature the newlineappropriate level sensors are selected. newline newline