How to configure a Rosemount 3051S HART to measure flow

One of the most common uses of differential pressure (DP) transmitters is to measure flow. However, you have to set it up properly to get the right readings.

Here we’ll tackle the Rosemount 3051S with the HART protocol. In this article, we’ll assume you’ve already installed it. We can talk about installation in another article. Let’s configure!


After installing your Rosemount 3051S in your process, you need to configure your device to send the right variable. I could explain all the equations and principles, but that would take a while. And you probably have a good grasp on fluid mechanics by now, if you’re installing flow meters.

The important thing to know is that to measure flow with a DP transmitter, you need the square root value, not the linear one. And that’s exactly what I’ll show you how to do on both the HART communicator and the AMS Trex. So here we go!

Oh wait, I almost forgot to warn you that before doing any changes, you need to set the application loop to manual. The field communicator and AMS Trex usually warn you to do so, but the warning itself doesn’t change the loop to manual. Okay, now that you set the loop to manual, let’s move on.

HART Field Communicator

On the “Home Page” you should see three menu options:

  • Overview, which shows you the settings applied to the 3051S
  • Configure, where you can access all the device configurations
  • Service Tools, where you can see alerts, charts, and so on
Rosemount 3051S
Courtesy of Emerson Automation Solutions

To set up the Transfer Function to square root, choose “Configure,” then “Manual Setup.” Inside the “Manual Setup” menu, the first item should be “Basic Setup,” so click on it.

Now select “Transfer Function.” There you’ll have the “Square Root” option. Select it and you’re done! Or you can keep going and set the low cutoff to avoid unwanted readings from low flow or noise on the pipeline. But this covers the basics.

Now that you know all the steps, I’ll give you another tip – the fast keys  2-2-1-4 will get you to the same place.

AMS Trex

Besides the HART Field Communicator, you can use another handheld called the AMS Trex. This intuitive handheld has a simpler user interface.

Rosemount 3051S
Courtesy of Emerson Automation Solutions

To set the Transfer Function to square root like we did on the Field Communicator, just access the device through the Field Communicator option and select “Configure” from the menu. Then go to the “Basic Setup” tab, and you should see a drop down list. Choose “Xfer fnctn,” then select the square root output. Click “Apply” and a warning should come up. Read it, then select Yes. Tada, all done!

Think you can use one of these methods to get your flow measured? Hope so, but if you have any questions, feel free to drop a comment below and I’ll help you out!

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