Process Reaction Curve is a chart used in Process Identification Procedure (PID). It is utilized in industrial systems to control variables which need to comply with setpoint adjustment. Examples of these variables are: indicators of temperature, pressure, level of a liquid, speed of movement and physical position of system elements. Once a variable deviates from a setpoint value it is necessary for the system to bring it back to desired value. A system has a controller (electronic element) that measures the variables and initiates this system to respond in a desirable way (controller causes a reaction to occur): it is necessary to tune this controller in a proper manner.
Process Reaction Curve Method is used for tuning a controller. Procedure requires a step change of the controller’s output that alters controlled variable, which is displayed on the computer monitor – then, taking into account the shape and magnitude of process reaction curve of the controlled variable, information for mathematical formulas is derived (process identification procedure). From a process reaction curve it is possible to derive the following values:
- Process Reaction Rate;
- Unit Reaction Rate;
- Effective Delay;