A current to pressure (I to P) transmitter is a device used to convert an electrical current signal (typically 4-20 mA) into a pneumatic pressure signal (typically 3-15 psi or 0.2-1 bar). This type of transmitter is commonly used in industrial control systems where pneumatic signals are used for actuation or control purposes.
Here's how a current to pressure transmitter works:
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Input Current Signal: The transmitter receives an input electrical current signal, usually in the range of 4-20 mA. This signal is typically generated by a control system or a sensor that measures a process variable such as temperature, pressure, flow, or level.
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Electrical Circuitry: Inside the transmitter, the electrical current signal is passed through circuitry that includes an amplifier and a control valve mechanism. The amplifier amplifies the input signal and modulates the control valve to regulate the output pressure.
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Pneumatic Output: The modulated control valve adjusts the flow of compressed air or gas to a pneumatic output port. By varying the flow of pneumatic pressure, the transmitter generates a proportional pneumatic pressure signal corresponding to the input current signal.
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Pressure Adjustment: The transmitter may have adjustments or trim pots that allow for calibration and adjustment of the output pressure range. This ensures that the pneumatic output signal accurately reflects the input current signal over the desired range.
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Output Pressure Signal: The pneumatic pressure signal generated by the transmitter is typically standardized to a specific pressure range, such as 3-15 psi or 0.2-1 bar. This standardized signal can be used for actuation of pneumatic control valves, positioners, actuators, or other pneumatic devices in the control system.
Overall, a current to pressure transmitter converts an electrical current signal into a pneumatic pressure signal, allowing for seamless integration of electronic control systems with pneumatic actuation devices in industrial automation and control applications.
