Temperature controller is a kind of instrument used to control temperature. It works by taking an input from a temperature sensor and connects with an output from elements such as heaters. Temperature controller system depends on a controller in order to accept temperature sensor input. When selecting a controller there are some factors to be consider. These include temperature range and type of input sensor, output, control algorithm and the kind and number of outputs.
The device controls temperature by comparing process variable with the set value and error or deviation. Temperature controllers to select the required heating use the error or cooling needed in order to bring the temperature to certain level. When all calculations are complete, the controller will produce signals showing the changes needed. Manipulated value or the output signal is always connected to the fan, heater or control valve. Injection of heat from the process is the function of output signal. Temperature controlled system are made from four forms of Temperature controllers. These are the oven, the heater, controller and the thermometer.
Normally, the main function of temperature controllers is to measure the temperature from the thermometer and weigh it to the set point. In order to maintain constant temperature the heater should remain switched on when calculating the amount of time. Some times the amount of time needed for the heater to maintain the process temperature may be altered by factors such as the size of the heater, ambient temperature, size of the oven, air circulation within the oven, hair humidity and the surrounding insulation.
Types of controllers:
There are three types of controllers. They include proportional, PID and ON OFF controller. In order to control the process the system will use one type depending on the controlled system. On/Off Controller is the easiest type of temperature control. Its output is either on or off without middle state. It will only switch the output when the temperature is above the set level. It always uses where precision control is not necessary, and for temperature alarm, and when you do not want to switch on and off energy all the time.
Proportional Control is formulated in order to eliminate On/Off control cycling. It reduces the average power that is supplied to the heater when is almost to the set point. Finally, PID Control type combines proportional control with two adjustments and will assist the unit to compensate system changes. It has the proportional, integral and derivative controls terms that are adjusted to a specific system using trial and error. It is preferable to use the systems with small weight and those systems that can quickly react to any energy changes done to the process.
Temperature controller applications:
Temperature controllers have many benefits. It is used for managing operations such as machine packaging and molding injection machines. Hospitals or health care temperature controllers are used for accuracy on equipment such as laboratory test tools, incubators, refrigerators, crystallization chambers and test chambers where specimens needs certain temperatures.
Food and beverage use these controllers in order to regulate temperature. The common places that require temperature controllers include baking ovens, cooking, brewing, sterilization and blending. Plastic manufacturers need controllers to monitor and control the plastic temperatures.