PID Temperature controllers Programming Video- Pyro

What is a PID Temperature Controller? Process controllers use PID temperature control to improve process accuracy. PID temperature controllers work using a formula to calculate the difference between the desired temperature setpoint and current process temperature. Then predicts how much power to use in subsequent process cycles to ensure the process temperature remains as close to the setpoint as possible by eliminating the impact of process environment changes. PID temperature controllers differ from On/Off temperature controllers. Where 100% power is applied until the setpoint is reached. At which point the power is cut to 0% until the process temperature again falls below the setpoint. This leads to regular overshoots and lag which can affect the overall quality of the product. Temperature controllers with PID are more effective at dealing with process disturbances, which can be something as seemingly innocuous as opening an oven door. But the change in temperature can then have an impact on the quality of the final product. When the PID temperature controller is set correctly, it will adjust for the disturbance and return the process temperature to the setpoint while lowering power as the temperature gets closer to the setpoint to prevent overshooting and the possibility of overheating the product. What is P, I & D? The three elements of the PID algorithm are the Proportional, the Integral, and the Derivative. These elements each relate to the variance in the process temperature versus the setpoint in a period of time. Proportional – the variance between the setpoint and the current process temperature Integral – the previous variance from the setpoint Derivative – the predicted future variance based on previous and current variance An engineer manually calculates these variances over time, or a temperature controller automatically does so using a PID formula. You need to apply the power to maintain the temperature at the setpoint. The Different Tuning Methods for PID Controllers. There are two primary ways of tuning a temperature controller with the PID values. An engineer manually works out the P, I & D variables and the level of power required in the process to maintain the setpoint. By entering target values and using the self-tune function the temperature controller automatically calculates the PID to directly control the process. In either case the PID formula provides a level of power to apply in the process to maintain the setpoint. The engineer either sets it or enters it. Temperature control applications in industry: Oven/Heat Treat: Temperature controllers are employed in furnaces, ceramic kilns, boilers, heat exchangers, and roasting ovens. Packaging. Plastics. Healthcare. Food & Beverage. Types of Digital Temperature Controllers On/off temperature Controller. Proportional Control. Proportional integral derivative control (PID)