If you want to know the features of temperature controller then this article will be helpful.

The temperature control system uses to control the temperature. The device output is on or off, not in the intermediate state. For heating control, the work turns on when the temperature drops below the set value and turns off when the temperature exceeds the set value. A good example is an application where the controller receives input from a temperature sensor and has an output connected to control elements such as heaters and fans. Controllers are usually only part of a temperature control system, and the entire system must be analyzed and considered when choosing the right controller.

Since the temperature exceeds the set value and the output state changes, the process temperature circulates continuously from below the set value up and down. This cycle occurs rapidly, an on-off differential or "hysteresis" is added to the controller operation to avoid contactor and valve damage.

This difference of temperature controller requires the temperature to exceed a certain amount before the output turns off or on again. The on/off differential prevents the output from "vibrating" or quickly and continuously interrupting if the cycle up and down the set value is too fast. On-off control is usually a system that cannot support frequent power on / off if precise control is not required and if the system is too heavy and the temperature changes very slowly. A special type of on / off control used for alarms is the limit controller. This controller uses a latching relay.

Proportional control

Proportional control is designed to eliminate the cycling associated with on / off control. This has the effect of slowing down the heater so that it does not exceed the set value, but it approaches the set value and maintains a stable temperature. This dosing action can be achieved by turning the output on and off for a short period of time. The dosing action occurs within the "proportional band" near the set temperature. For Bio-medical equipment repair take help of expert.

However, within the band, the output turns on / off at the ratio of the measurement difference of the set value. That is, the power-on time and idle time are the same. If the temperature is far from the set value, the on-time and off-time will change in proportion to the temperature difference. If the temperature drops below the set value, the output will be on for a long time. If the temperature is too high, the output will be off for a long time.

PID control

These adjustments, integrals, and derivatives are expressed in temporary units. It provides the most accurate and stable control of the three types of controllers and is best used in relatively low mass systems that respond quickly to changes in energy added to the process.