Transducers vs Transmitters

Almost everyone uses the terms “pressure transducer” and “pressure transmitter” interchangeably, but the two devices are technically not the same. A pressure transducer converts pressure to an electronic signal, while a pressure transmitter also amplifies, modifies, and sends that signal. Regardless of those differences, what’s important is to have the right output signal.

Many manufacturers and users do not differentiate between pressure transducers and pressure transmitters. However, these two types of pressure instruments are not technically the same.

Basically, a transducer measures pressure, load, force, or other states, and converts the reading into an electronic signal. A transmitter also converts a reading into an electronic signal, but it then amplifies, modifies, and sends that signal to a receiver.

Comparing Pressure Transducers and Transmitters

In a pressure transducer, a thin-film or piezo-resistive pressure sensor is mounted on a process connection. The transducer converts pressure into an analog electronic output signal, typically as a millivolt per volt output. These signals are not linearized or temperature compensated.

A pressure transmitter has additional circuitry that linearizes, compensates, and amplifies the signal from a transducer. The different signal types are typically voltage signals (e.g., 0 to 5 or 0 to 10 volts), milliamp (e.g., 4 to 20 milliamp), or digital. The instrument then can transmit the signal to a remote receiver.

Many pressure transmitters offer a variety of calibration options, including turndown and zero/span adjustment. Smart transmitters can be calibrated, tested, and reset remotely using a bus network.

Pressure Transducer or Transmitter: Which One to Choose?

Despite the differences between the two types of instruments, it really doesn’t matter what people call it or which one they use. What’s more important is whether the device suits a particular application and offers the needed output. Accuracy, range, working temperature, and the medium are all determining factors when selecting the right pressure instrument for an application.

As for the output signal, here are some factors to take into account:

  • Typical mV outputs do not have temperature characterization.
  • A current signal is more immune to interference and noise than a voltage signal.
  • A current signal can also travel farther.
  • An analog signal is just the pressure reading.
  • A digital signal allows a user to collect more information and other variables besides pressure.
  • The input card of many control systems accepts only amplified signals.

The bottom line: Get the pressure device you need, regardless of what it’s called. For expert advice on the best sensors to use with your particular application, contact the pressure measurement professionals at WIKA USA.



7 Responses to
  1. Swaminathan Sundaram Govindarajan

    I am planning to install PLC for my injection moulding machine where to measure the locking force I am planning to use Pressure Transducer. Now I come across pressure tramsmitter.
    Please suggest which I should use whether transducer or transmitter.

    • Robert Lukat

      Hello,

      While there are technical differences between a transmitter and a transducer, the two terms are often used interchangeably. If you are adding a PLC to your control system, the important thing to make sure of is that the output signal from the transmitter or transducer is a signal that works with your PLC.

      Robert

  2. Mahdi

    Greetings,
    I want to opt a conventional pressure transmitter that can conduct on-time measurements in adjustable time intervals as well as a data acquisition system that can provide a glut of pressure data to PC. Kindly advise in case you had any ideas.
    Sincerely your’s
    Mahdi

    • Robert Lukat

      Hello Mahdi,

      We would need some information about what you currently have as a data acquisition system and what kind of data you are looking for. WIKA does not currently provide a data acquisition system, but does make a wide range of analog pressure transmitters that can be combined with a DAQ to provide pressure data. We do have a precision transmitter that will connect via USB to a PC and using our data logging software allow you to pull data I have attached a link to our data sheet for this model below:

      https://www.wika.com/en-en/p_30_p_31.WIKA

      Robert Lukat

  3. Morteza

    Hi

    which one is better to measure dynamic pressure of cylinder in reciprocating compressor for monitoring of compressor via PV diagram? pressure transducer or pressure transmitter?
    is it essential that a compressor manufacturer consider an appropriate provision ( such as a valve tap ) for installation of pressure transducer or transmitter ( each one is better )?

    Thanks in advance

    • Faith Bergeron

      Hi Morteza. Thank you for your comment. A product manager should be reaching out to you shortly regarding your question.

    • Faith Bergeron

      Hello Morteza,

      As many people will use the terms transmitter and transducer interchangeably, There really is no answer for “which is better to use in my application”. The key things to take into account are the response time and accuracy that is needed in the application. Depending on the output signal you need to use to communicate with your controller/plc could also impact the device you require. Depending on the answers to above, either unit could be used.

      Please feel free to contact me directly if you have additional questions.

      Best regards,

      Robert Lukat
      Product Manager – Electronic Pressure Measurement


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