Pressure Transmitter Explained | Working PrincipleLearn about a very versatile instrument used in industry today – the Pressure Transmitter
In this article, we’re going to introduce you to a very versatile instrument used in industry today – the Pressure Transmitter.
Transmitter vs Transducer
First of all, let’s discuss the terms Transducer and Transmitter. Some people will tell you that a Transducer and a Transmitter are the same things and therefore the terms are interchangeable.
If you are curious, conduct a web search of the two terms and you will be surprised at the wide range of results!
A transducer is a device that converts one form of energy to another.
For example, an electrical transducer converts a sensed physical variable like temperature into an analog electrical signal.
A transmitter is a device that converts the electrical signal from the transducer into a much larger electrical signal that can be sent over a long distance to a PLC or a DCS.
Transmitter output signal
The transmitter output signal is usually a range of voltage (1 to 5 V) or current (4 to 20 mA) which represents the 0 to 100% of the sensed physical variable.
A Pressure Transmitter is an instrument connected to a Pressure Transducer.
The output of a Pressure Transmitter is an analog electrical voltage or a current signal representing 0 to 100% of the pressure range sensed by the transducer.
The actual sensor part of the transducer which makes contact with the pressure being sensed is based on several technologies and materials such as Strain Gauge, Capacitance, and Potentiometric.
The actual process is separated from the sensing material by a measuring diaphragm.
The type of sensor chosen is decided by the application and environment it is being used in.
Pressure transmitters can measure absolute, gauge, or differential pressures.
Absolute pressure is referenced to a perfect vacuum which is considered 0 psi! We express vacuum pressure as 0 psi (a).
Atmospheric pressure is usually about 14.7 psi (a).
The most common pressure measurement is gauge pressure which is the total pressure minus the atmospheric pressure.
Atmospheric pressure is 0 psi (g).
As we’ve discussed in our previous articles, the versatility of a differential pressure transmitter gives us the flexibility to measure level and flow as well as pressure.
Pressure Transmitter example
Let’s have a look at an example of a Pressure Transmitter measuring process pressure of gasses in a pipeline.
The Pressure Transmitter will send a current signal to the PLC which represents the process pressure.
The Pressure Transmitter is calibrated to provide a current range of 4 to 20 mA for a Process Pressure range of 0 to 350 psi.
Let’s review what we’ve discussed.
– Some people will tell you that a Transducer and a Transmitter are the same things and therefore the terms are interchangeable.
– A transducer is a device that converts one form of energy to another.
– A transmitter is a device that converts the electrical signal from the transducer into a much larger electrical signal that can be sent over a long distance to a PLC or a DCS.
– A Pressure Transmitter is an instrument connected to a Pressure Transducer.
– The output of a Pressure Transmitter is an analog electrical voltage or a current signal representing 0 to 100% of the pressure range sensed by the transducer
– Pressure transmitters can measure absolute, gauge, or differential pressures.
You might want to review two of our other articles:
Want to Learn More?
Newcomers to RealPars have free access to one of our online courses.
Also, for a low monthly fee, you’ll get full access to an exclusive library of courses on PLC programming and industrial automation topics as well as new fresh out of the oven videos each and every week. These courses are all member-exclusive and are not shared anywhere else on the internet.
If you would like to get additional training on a similar subject please let us know in the comment section.
Check back with us soon for more automation control topics.
Got a friend, client, or colleague who could use some of this information? Please share this article.
By Ted Mortenson
Posted on July 13, 2020
By Ted Mortenson
Posted on July 13, 2020
In this blog post, you’ll learn about the mindset that helped me getting a PLC programming job with NO experience. This is my personal experience as someone who searched for a job in this field and as an employer who reviews resumes and interviews candidates for a variety of projects. So let’s get started!
In this article, we're going to introduce you to the NX and NJ series of Omron Controllers. The NX and NJ controllers are powerful as they combine both PLC and motion control functions into one package.PLC + Motion controlBefore we dive into the specifics of the...
There are many types of process flow meters. Coriolis mass flow meters; positive displacement flow meters, such as turbine meters; and volumetric flow meters, like the ultrasonic flow meter, just to name a few.In fact, there are at least eighteen different types of...
Learn how to program PLCs, install and wire industrial devices, and at the same time purchase them online.
+31 10 316 6400
Mon - Fri 8:30 am to 5:30 pm (CET)
Rotterdam Science Tower, Marconistraat 16,
3029AK Rotterdam, Netherlands
Help & Support
© 2021 RealPars B.V. All rights reserved.
Created with coffee and tea in Rotterdam.