Product Review: Rosemount 5408 Level Transmitter

Let’s talk about Emerson’s Rosemount 5408 ! No, wait. Let’s talk about why you might need one first. Level measurement is a critical process variable in most industries out there.

Visaya has a bunch of product reviews covering different working principles and brands that can fit in a new application. If you want to check some out, then go to our Product Reviews section and search for a device to get more details before you buy it. We also have #WishIknews and Q&As where we answer general questions about measuring level.

Okay, back to the Rosemount 5408 ! This level transmitter is a fairly new product, so we’ll have a peek and see how it can fit in your process.  Stick with me and let’s dive into the features.

Disclaimer: This product review examines only features, not performance. If you’ve used this device, feel free to share your experience in the comments. This content serves the purpose of providing information if you want a new device.

Whatcha got there?

This device comes in two versions, the standard one and the safety instrumented system (SIS) one. Regardless of the version you pick, its design closely resembles some of Emerson’s other devices. Some folks would call that familiar, others would call it lazy. What do you think?

You get loop power in both versions (standard from 12 to 42.2 volts and SIS from 12 to 30) but no local setup. Of course, if you’ve ever used another Emerson device, you’re probably aware of this lack. But you can set it up traditionally using a handheld like the DPI 620 Genii, Field Expert SMT70, or even the Field Expert SMT70

image of Rosemount 5408 Level Transmitter
Courtesy of Emerson

The Rosemount 5408 can measure liquids, solids, slurries – all kinds of stuff. And it operates with a principle known as Fast-sweep Frequency Modulated Continuous Wave (FMCW). Basically, the device regularly emits a signal that keeps changing frequency. So the transmitter will subtract the signal reflected by the signal emitted at that moment to give you a low-frequency signal proportional to the surface distance. Make sense? Good!

The dielectric constant (DC) of the product still matters, if that thought crossed your mind. And some conditions, such as foam, turbulence, and  dust,  may apply too. You’ll have to check those in your process and the manual.

What can it do?

It can measure level in a vast array of processes, industries, and products. The standard 5408 has a range of 40 meters, and the SIS version can reach 25. Moreover, it works in 26 GHz, although the beam angle (α) will differ depending on the antenna size.  Check these numbers out:

  • 2-inch (DN50) cone/process seal = 18°
  • 3-inch (DN80) cone/process seal = 14°
  • 4-inch (DN100) cone/process seal = 10°
  • 8-inch (DN200) parabolic = 4.5°

The manual has a table with the beam width, which also varies depending on distance and antenna size.

image of how Rosemount 5408 Level Transmitter works
Courtesy of fccid

Sadly, the device only has analog and HART. If you want FOUNDATION Fieldbus, PROFIBUS, or whatever, you need to hop onto our device page. On the upside, you can communicate wirelessly using Emerson’s THUM adapter, although it can’t power the device. If you want an adapter able to power it and send process data out, you need to have a sniff round Pepperl+Fuchs or Endress+Hauser.

Finally, it comes in two housing types, aluminum and stainless steel. It also has a bunch of process connections, antennas, electrical connections, and seal material. Give the datasheet a stare if you want to know more.

Why should I care?

Because the Rosemount 5408 will measure level in nearly every segment you can imagine. The device can handle pressures up to 100 bar and temps from -60 to 250 degrees Celsius too.

image of Rosemount 5408 Level Transmitter
Courtesy of lakesidecontrols

Additionally,  it has an accuracy of +-2 millimeters, and you can get an assortment of certifications and approvals, such as ATEX, IECEX, CSA, and INMETRO.


Sure, the Rosemount 5408 has its limits, but you still can integrate it in most systems out there. If you want to read more about it or compare it to another option, you can visit the device page at Visaya or poke those devices on the right side of your screen.

This video will tell you more about the Rosemount 5408 :


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