The laboratory is an introduction to the dynamic behavior of a pilot-scale level control system and in the operation of PID feedback controller. The principle aim of the experiments is to understand the role and operation of the main components in a feedback loop: (i) sensor, (ii) actuator (control valve) and (iii) controller.

The plant to be controlled is a liquid surge tank with a pump in the outlet stream. To an acceptable approximation (which will be tested in the laboratory), the liquid flow from the tank is independent of the liquid level in the tank. The flow of liquid entering the tank is independent of the tank's liquid level; as a consequence, the tank acts as an integrator, integrating the difference between the flow in and the flow out. Control action is needed to stabilize the liquid level. The process control lab is shown in Figure 1.

The lab is used for undergraduate teaching. It is part of the Instrumentation and Control course taught for second year students. The complete lab manual of can be downloaded from here.