Hydrocarbon / acid interface measurement in acid settlers

Between the two products, an intermediate phase is present. To control the layer thickness of the intermediate phase, and to ensure that the drained products are not contaminated, the EmulsionSENS Multiphase Level Measurement system from Berthold is used to detemine the positions of the different product layers. Offering two different arrangements, either the product density at specific heights (aligned arrangement) is provided, or the level of the various phases can be measured continuously (staggered arrangement). This noncontact technology is ideal for the harsh acidic process.


Customer benefits

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




  • Multiple detectors and sources distributed along the measurement range
  • Fixed installation, no moving parts, and therefore robust system
  • Very precise density information at corresponding detector height, density accuracy ≤0.002 g/cm³ (aligned arrangement)
  • Or level measurement of the interface layers, level accuracy +/- ≤25 mm (staggered arrangement)
  • Maintenance-free
  • 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 the acid storage drums. Measuring the acid level is important to fulfill the highest safety standards, especially in an emergency case where all acid has to be pumped back into this drum. It is of extreme importance that the level measurement be reliable and respond quickly. 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 emergency shut down cases



  • Noncontacting, nonintrusive level gauge
  • Easy to install on existing tanks, without modification or process downtime
  • Repeatable and stable measurement due to patented stabilisation technology
  • No recalibrations required

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

X-ray 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 detectors available

The SENSseries LB 480 series offers versions that are certified for use in SIL2 applications. SIL3 is achieved by adding an identical redundant SIL2 detector using the same source for homogenous redundancy. The certificate covers all measurement applications, from high level or low level alarms to continuous level. Thus the safe measurement of critical processes is guaranteed.

More about SIL


Further applications

By using the EmulsionSENS Multiphase Level Measurement, operators can safely control the acid level while ensuring that acid is not carried over and hydrocarbons are not removed from the bottom of the settler. Minimize vessel leak points by using radiometric level measurement in various distillation column bottoms such as the 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