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.
9 Responses to
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.
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.
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.
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:
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
Hi Morteza. Thank you for your comment. A product manager should be reaching out to you shortly regarding your question.
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.
Product Manager – Electronic Pressure Measurement
I only have experience working with gage and absolute pressure transducers, and each instrument requires some way to compensate for barometric pressure. Typical installations are open water reservoirs or concrete lined channels. Do pressure transmitters no longer need barometric pressure compensation or would that need to be handled by its controller?
Yes, transmitters and transducers do still require barometric compensation. Typically low pressure gauge reference units (<~1000 psi…depending on full scale accuracy of the unit) will have some sort of vent to allow for compensation with changes in barometric pressure. Higher pressure units do not always have this vent as changes in barometric pressure are not significant enough to effect the overall units accuracy. For an absolute referenced transmitter or transducer a venting is not required as the reference point is a full vacuum and not atmospheric pressure.
Please let me know if you have any additional questions.