Description

• This instrument is used to control temperatures, mainly without extensive operator involvement.
• A controller in a temperature control system will accept a temperature sensor such as a thermocouple as input and compare the actual temperature to the desired control temperature, or set-point.
• It will then provide an output to a control element.
• It does this by first measuring the temperature (process variable), it then compares it to the desired value (set value).
• The difference between these values is known as the error (Deviation).
• Temperature controllers 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)and is normally connected to a heater, control valve, fan or some othe final control element which actually injects or removes heat from the process.
• These are mostly used in industrial applications as well as in restaurants, laboratories, hospitals and on different places for temperature controlling purposes etc.