Selecting Best Solids Level Measurement Technology - Emerson Automation Experts

Selecting Best Solids Level Measurement Technology

This being Engineers Week, I wanted to celebrate all the engineers with a recap of a good technical note on solids level and volume measurement. The paper, Measuring Level and Volume of Solid Materials, describes the various technologies and considerations for the selection of solids level and volume measurement.

Emerson's Ludvig Bengtsson

Ludvig Bengtsson
Marketing Engineer

Emerson’s Ludvig Bengtsson shared his insights for this technical note. Three main technologies used for solids measurement include guided wave radar, non-contacting radar and acoustic 3D solids scanners.

When measuring solids there are many considerations for engineers based on the characteristics of the solids. One characteristic is the evenness of the surface.

Guided wave radar reflections are least affected by surface unevenness and non-contacting are most affected, since the radar signal may bounce at an angle.

Solids level and volume measurement reflections

Other characteristics impacting the quality of the measurements include dielectric constant of the solid, bulk density, filling location, dust, condensation, and whether level or volume is the measurement sought.

A reflected radar signal is impacted by dielectric constant but not bulk density. Conversely acoustic 3D solids scanners are not affected by dielectric constants but are by bulk density. Radar and acoustic measurements handle dust conditions better than alternative technologies such as ultrasonic and laser measurement. If the dust is sticky, consideration must be given to non-stick materials for the antenna surface.

For vessels with condensation, guided wave radar is not affected by it. Non-contacting radar may require air purging systems. Acoustic 3D solids scanners have self-cleaning mechanisms to manage these conditions.

Rosemount 5708S 3D Solids Scanner

Rosemount 5708S 3D Solids Scanner

If solids level measurement is the primary consideration and the application involves fast level changes, radar devices are a good choice unless the dielectric constant is too low or the distance between the radar and the level surface is great, then a Rosemount 3D Solids Scanner is a good choice.

If volume measurement is sought, typically for inventory management applications, 3D solids scanners are best. Multiple measurements help to integrate uneven surfaces and provide more accurate volume measurements. The Rosemount 5708V is a good fit for medium silos and the Rosemount 5708S for medium to large silos.

Rosemount 5303 Guided Wave Radar

Rosemount 5303 Guided Wave Radar

The technical note provides a comprehensive table with these considerations to help in the selection process. It also includes best practices in mounting and installation for guided wave radar such as the Rosemount 5303 transmitter, non-contacting radar such as the
Rosemount 5402 Non-Contacting Radar

Rosemount 5402 Non-Contacting Radar

Rosemount 5402 and 5600 transmitters and the Rosemount acoustic 3D solids scanners.

You’ll want to read the technical note to review these considerations and best practices in the selection of the best technology for your solids level and volume measurement applications.

There is an application evaluation form to help in the section process and to engage experts who can assist.

You can also connect and interact with other level measurement experts in the Level group of the Emerson Exchange 365 community.


  1. Jonas Berge says:

    It’s quite fascinating how the solids scanner builds a 3D image showing how the product is stacking up unevenly inside the silo. From the 3D image you can see how it forms a pile when the silo is loaded, and how it forms a crater with some product clinging to the walls as it is emptied. So even if the product surface is far from even, you can still tell how much is truly in there.

    If you’d like to learn more about the 3D solids scanner solves solids tricky measurement challenges there is a webinar coming up on Tuesday March 17, 2015. After the presentation you’ll have a chance to ask questions to the speaker directly. Register here:

  2. I’ve read everywhere how it depends on the application, although I think your perspective is much more direct, it depends on the “evenness of the surface”. I read about the level measurement in silos ( and wondered which could be the best technology for a silo in the food industry

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