Microcontroller Based PID Controller

Libratherm offers two field proven models of Auto tune PID controllers. One is a microprocessor based PID-300 and other is microcontroller based model PID-723. PID controllers are superior compared to simple digital onoff and time proportional controls. They are widely used for applications requiring precise and very accurate temperature control of a heating or cooling systems which undergoes frequent disturbances.
For temperature sensing, PID-300 accepts either thermocouple, RTD temperature sensors, or voltage or current signals. While PID-723 has facility to accept fixed or universal input, where type of input can be selected by the user depending upon requirement. In all 8 inputs are user selectable like 5 types of thermocouples J,K,R,S, B and RTD(Pt-100), (0-5)V and (4-20)mA. This facility allows user to use the same controller for varied temperature control applications, by merely changing the sensor type.
For controlling purpose, both the models provides switching control outputs of relay contacts, or solid state relay driver or Triacs – (for controlling switching devices such as contactors, solenoid valves or solid state relays), as well as analog control outputs of (4-20) mA or (0-5) V which can be used to control a Thyristorized power pack (for electrical heating system) or to control the position of a modulating motor valve ( for oil or gas fired heating system). Dual PID outputs for both direct and reverse actions are also available for applications requiring heating and cooling control.
Both the models can also be used for any other process control applications such as - flow control, pressure control, level control, humidity control, pHORPConductivity control etc… by accepting inputs from respective process transmitters or transducers. Libratherm also offers ready to use instrumentation control panel incorporating PID controller with other required panel accessories.
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