Hydrocarbon / acid interface measurement in acid settlers

Between the two products an intermediate phase is present. To control the layer thickness of this phase and to ensure that the withdrawn products are not contaminated, the multiphase level measurement system EmulsionSENS from Berthold is used. Due to two different arrangements either the product density at specific heights (aligned arrangement) is provided or the level of different layers can be measured continuously (staggered arrangement).


Customer benefits

  • Online monitoring of separation process
  • Reliably prevent acid carry-over
  • Increased process safety
  • Virtually no need for maintenance related work, keeping work time in the acidic area to a minimum




  • Multiple detectors and sources distributed along the measurement range
  • Accuracy of density profile: <0.002 g/cm3
  • Accuracy of interface level measurement: +/- 25 mm
  • Immune tointerfering radiation, with XIP, or continuing operation during weld inspections with RID
  • Optional: control unit for visualization and operation

Level & level switch measurement in acid storage drums

The acid used in the alkylation process is stored in acid storage drums. Measuring the acid level is important to fulfill the highest safety standards, especially in an emergency situation where all acid has to be pumped back into this drum. Therefore, it is of extreme importance that the level measurement is reliable and fast responding. In addition to the level gauge, Berthold also provides a radiometric level switch for high level alarm.

Customer Benefit

  • Real-time information on acid level
  • Reliable control of acid process cycle
  • Increased safety in case of emergency shutdown


  • Non-contacting, non-intrusive level gauge
  • Immune to interfering radiation, radiation with XIP, or continuing operation during weld inspections with RID
  • Repeatable and long-term stable measurement due to patented sensitivity stabilization
  • Optional SIL 2 / SIL 3 certified

Long-term stability

A reliable measurement, requiring no recalibration, is vital for the operation of the alky unit, and is our highest priority. Berthold’s detectors offer stability in the face of changes in ambient temperature. Even drastic temperature shifts, e.g. from winter to summer do not cause measurement drift. Our patented method for detector stabilization compensates for temperature changes and aging.

Detector Stability

Radiation Interference Protection (XIP)

With this function, weld tests no longer cause sudden fluctuations in the measured value. When weld tests are detected, the measured value is frozen until the external radiation event ends. A digital output can be set to signal the detection of interfering radiation. 
All of our level measurement detectors are equipped with XIP.

More about XIP


SIL certified option

If you want to continue to measure with impending external radiation, then the "LB470RID" version is required. The measurement continues without interruption, even if external radiation is present. External radiation is detected due to its different energy. The detector then changes to a second measuring channel and continues the measurement without error. This patented process makes the system particularly reliable. 

More about SIL


Further applications

By using EmulsionSENS, operators can safely control the acid level, ensuring that acid is not carried over or hydrocarbons are not removed from the bottom of the settler.
Minimize vessel leak points by using radiometric level measurement in various column bottoms such as depropanizer, acid rerun column and acid storage/emergency dump drum.



Measurement solutions for the refining industry Industry brochure

English | PDF | 2.6 MB

Multiphase level and interface measurement Product brochure

English | PDF | 1.2 MB

Multiphase level measurement Whitepaper

English | PDF | 5.6 MB

Berthold's measurement solution


Solution for monitoring transition phases or the height of multiple phases