In many industries process such as petro chemical industries, paper making industries

and water treatment industries are using the tank system to control the liquid level. The

liquid level must be controlled by the proper controller. The objective of the controller in

the level control is to maintain a level set point at a given value and be able to accept

new set point. The conventional proportional- integral- derivative (PID) is commonly

utilized in controlling the level. On the other hand, the fuzzy logic controller (FLC) is

also popularly implemented in many practical industries application.