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    How A Current To Pressure Transducer (I - P) Works - Learning Instrumentation An

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    LeDu
    A current to pressure (I/P) transducer converts an analog electrical signal into a proportional pneumatic pressure output. It uses an electromagnetic force balance principle, where a coil produces a magnetic field that controls a flapper valve and precision nozzle to create backpressure and output pressure. An I/P transducer is commonly used to control valves and actuators through receiving an electrical signal from a controller and producing a proportional pneumatic signal.

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    How A Current To Pressure Transducer (I - P) Works - Learning Instrumentation An

    Uploaded by

    LeDu
    43 views2 pages
    A current to pressure (I/P) transducer converts an analog electrical signal into a proportional pneumatic pressure output. It uses an electromagnetic force balance principle, where a coil produces a magnetic field that controls a flapper valve and precision nozzle to create backpressure and output pressure. An I/P transducer is commonly used to control valves and actuators through receiving an electrical signal from a controller and producing a proportional pneumatic signal.

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    How a Current to Pressure Transducer (I_P) Works _ Learning Instrumentation An

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    A current to pressure (I/P) transducer converts an analog electrical signal into a proportional pneumatic pressure output. It uses an electromagnetic force balance principle, where a coil produces a magnetic field that controls a flapper valve and precision nozzle to create backpressure and output pressure. An I/P transducer is commonly used to control valves and actuators through receiving an electrical signal from a controller and producing a proportional pneumatic signal.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    43 views2 pages

    How A Current To Pressure Transducer (I - P) Works - Learning Instrumentation An

    Uploaded by

    LeDu
    A current to pressure (I/P) transducer converts an analog electrical signal into a proportional pneumatic pressure output. It uses an electromagnetic force balance principle, where a coil produces a magnetic field that controls a flapper valve and precision nozzle to create backpressure and output pressure. An I/P transducer is commonly used to control valves and actuators through receiving an electrical signal from a controller and producing a proportional pneumatic signal.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
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    How a Current to Pressure Transducer (I/P) Works

    A “current to pressure” transducer (I/P) converts an analog signal (4 to 20 mA)


    to a proportional linear pneumatic output (3 to 15 psig). Its purpose is to
    translate the analog output from a control system into a precise, repeatable
    pressure value to control pneumatic actuators/operators, pneumatic valves,
    dampers, vanes, etc.

    The I/P converter provides a reliable, repeatable, accurate means of converting


    an electrical signal into pneumatic pressure in many control systems. Models of
    this device are usually available in direct and reverse action and are field
    selectable with full or split range inputs or output as the case may be.

    The most common application of an I/P transducer is to receive an electrical


    signal from a controller and produce a proportional pneumatic output for
    operating a control valve or positioner. The device can be mounted on the wall or
    a pipe stand or directly on the valve actuator. Where the device can withstand
    vibrations, they are directly mounted on the valve actuator. In many instances,
    the device is remotely mounted on instrument pipe stands to reduce vibrations.

    Operating Principle
    The I/P converter uses an electromagnetic force balance principle to change
    electrical signals into pneumatic signals. Typically, a 4 – 20mA input is converted
    into a 3 – 15pisg output. The operating principle of the I/P transducer is shown
    below:

    As shown above, a coil produces the magnetic field. Within the coil is a deflector
    motor with a flapper valve attached that operates against a precision nozzle to
    create a backpressure on the servo diaphragm of a booster relay. The input

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    current flows in the coil and produces a force between the coil and the flapper
    valve, which controls the servo pressure and the output pressure.

    Zero adjustment of this device is made by turning a screw that regulates the
    distance between the flapper valve and the air nozzle. Span adjustment is made
    by varying a potentiometer, which shunts input current past the coil. The output
    signal of an I/P transducer easily falls to bleeds pressure upon failure of the
    electrical signal. This makes it easy to detect electrical failure signal in the
    device.

    Troubleshooting and Calibration Tips


    Most I/P converters are supplied instrument air of about 20psig above the
    required output of the device. An inoperative or poorly performing I/P transducer
    may just be having problem with its air supply. So to effectively troubleshoot this
    device, slightly open the air set drain and check that the supply air is dry and oil
    free. Checks can also be made on external bleed opening to verify that it is clear
    and free from obstruction and that it is venting properly.

    This device is calibrated in much the same way as you calibrate a pressure
    transmitter. Please see How to Calibrate a Current to Pressure Transducer for a
    detailed guideline. In calibrating the I/P transducer, you provide an accurate input
    and check the output with a test gauge or any other test device. Check Zero,
    Span and Linearity and adjust as necessary. You can use either an accurate
    current generator or an accurate voltage generator with a compulsory precision
    resistor of 250 ohms and half watt(1/2W) as power rating.
    If you have found this post on I/P transducer useful, please endeavour to share it.

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