What is Radiometric Level Measurement?

Extreme process conditions can have an adverse effect on various measuring principles over time, causing them to become obsolete. Radiometric level measurement, however, utilizes Gamma rays to measure the level of a process due to their high power and deflection-resistance.

How Does it Work?

Radiometric measurement devices enable non-contact point level detection, continuous level, interface and density measurement tasks can be solved, even under extreme process conditions. By placing a gamma detector on one side of a vessel and measuring the radiation emitted through to the other side, users can obtain a reliable indication of level within that vessel.

The radiation of the gamma source container is emitted almost unattenuated in one direction only, and is damped in all other directions, guaranteeing the highest safety for personnel and a reliable measurement.

Radiometric level measurement works well in a variety of applications, including desalters.


In petroleum refineries, desalters are typically installed in the heat exchange train which heats incoming crude oil before it flows through a fired heater and into the distillation tower. They are the first and one of the most important steps in the refining process.

Desalting is imperative to reduce corrosion, plugging and fouling of equipment, as well as to prevent contamination of the catalysts in processing units. Even in small concentrations, salt and water in the subsequent downstream process can have many negative effects, including:

  • Salt leads to corrosion in the subsequent downstream process
  • Chlorides can hydrolyze to HCL, which is extremely corrosive
  • Salt accumulates in stills, heaters and exchangers which can lead to fouling, requiring expensive cleanup
  • Too much water entering the preheat train can lead to vaporization and cause interference/noise and pipe variations due to high pressure

Like most separation processes, there is no clear indication between two substances since separation happens continuously within a vessel. Instead, there is an oil/water transition zone – known as the emulsion layer. Standard level measurement cannot accurately measure the top and bottom of the emulsion layer due to variations in the properties of the fluids and the emulsion layer. This is where Radiometric level measurement using Gamma devices comes into play.

Benefits of Radiometric Level Measurement in Desalters

Operators who use Endress+Hauser’s Radiometric Level Measurement enable detailed insight into the medium interface levels and emulsion layers within a desalter. Due to the high energy of gamma rays, this level measurement technology is virtually unaffected by buildup and offers users a new way to see clearly inside a desalter.

Benefits include:

  • More effective desalting process
    • Due to “monitored” emulsion layer of a certain thickness and position
  • Less fouling and corrosion of equipment
  • Longer run times
  • Reduced maintenance requirements
  • Reduced frequency of desanding
  • Increased cost savings thanks to reduction in chemical additives
    • Chemical additives – expensive agents which can have negative side-effects on subsequent downstream processes
  • Lower operating temperatures
  • Lower fuel costs
  • Reduction of water means a decrease in pumping costs
  • Crude oils of different qualities and densities can be used since the system automatically adjusts to changing process conditions

How to Learn More

Interested in learning more about how Endress+Hauser’s Radiometric level measurement technology can improve level measurement readings within your process? Contact Eastern Controls’ dedicated application specialists today at sales@easterncontrols.com or at 610-325-4600.

Read more about desalters in Endress+Hauser’s whitepaper: Technologies for Desalters.

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Manufacturer: Endress+Hauser
Topic: Level Measurement

As the Mid-Atlantic representative for Endress+Hauser, Eastern Controls has the necessary training and experience to effectively demonstrate this device and answer questions you may have about its operation. For more information about this product and/or other products offered by the manufacturer that may benefit your process operations, please contact our sales group.