PID is short for "proportional plus integral and derivative control", the three actions used in managing a control loop. Process loop controllers use one, two or all three of these to optimally control the process system. PID control is used in a wide variety of applications in industrial control and process system management.
Download "Principles of PID Control and Tuning" from the Hile Controls website here.
Courtesy of Eurotherm. Eurotherm offers a wide range of single & multi-loop PID controllers.