The Essentials of Process Control (EPC) rangeof products takes students through the fundamentals and principles of processcontrol and progresses to give them a thorough grounding in the control ofphysical processes. Four independent process units demonstrate level, flow,temperature and pressure as the controlled variable. The concepts of closedloop control, including on/off control, proportional control, proportional/integraland proportional/integral/derivative (PID) control can be explored anddemonstrated. Some units also cover both time proportioning and analoguecontrol of the same parameter. Each process is supplied complete with softwarethat allows it to be controlled using a Windows PC via a USB connection. Theeffect of making changes to the system or to the controller configuration canbe quickly investigated by applying repeatable disturbances or step changes to theprocess. Comparison of the responses obtained with different control settingsclearly demonstrates the need for correct matching of the controller to thesystem characteristics. To demonstrate industrial control systems, two furthercontrolling devices are available, a full function commercial PID controllerwith auto tune, and a programmable logic controller (PLC). The plc has thecontrol algorithms implemented in ladder logic and so are fully accessible tothe user. Another fundamental aspect of process control is an understanding ofsensors and how they are calibrated. This is demonstrated by a sensorcalibration apparatus designed specifically to demonstrate this subject.