A temperature controller, as its name indicates, is a device that is used to control temperature. The temperature controller system has an input from a temperature sensor and has an output that is connected to a control element such as a heater or fan.
How does a temperature controller works?
The temperature controller reads an input (PT100, thermocouple or analog) and has a regulation output via relay, SSR or analog to control different regulation equipment.
To precisely regulate the process temperature without intensive operator participation, a temperature control system relies on a regulator, which accepts as input a temperature sensor. The temperature controller starts by comparing the actual temperature with the desired control temperature (called set value). The difference between these values is known as the error (Deviation).
The temperature controller use this error to decide how much heating or cooling is required to bring the process temperature back to the desired value. Once this calculation is complete, the controller will produce an output signal that effects the change required. This output signal is known as the (manipulated value).
What are temperature controllers used for?
The temperature controllers are special for ventilation and heating systems cause they are normally connected to a heater, control valve, fan or some other “final control element” which actually injects or removes heat from the process.
Types of temperature controllers:
There are three basic types of regulators: on-off, proportional and PID. Depending on the system to be regulated, the operator may use one type or another to regulate the process.
- On / Off temperature controller: An ON / OFF controller is the simplest form of temperature control. The regulator output is on or off, without an average state. An ON / OFF temperature controller changes the output only when the temperature passes through the set point.
- Proportional temperature controller:Proportional temperature control eliminates the associated cycle of on-off control. A proportional controller decreases the average power delivered to the heater when the temperature approaches the set point. This has the effect of decreasing the energy of the heater as it approaches the set point without exceeding it, maintaining a stable temperature.
- PID temperature controller:The third type of temperature control is the PID, which offers a combination of proportional with integral and derivative control. In fact, the acronym PID refers to a Proportional Integral Derivative control.