State of the art measurement technology

Level measurement system installed on vessel

Continuous level measuring principle by Berthold!

Gamma radiation, emitted from a collimated source is attenuated by product as it passes through the vessel. The amount of gamma which makes it through  the vessel is measured by a highly sensitive detector, mounted on the opposite side of the vessel. As the radiation source, detector sensitivity, and geometry do not change, the amount of attenuation is only affected by the change in product level.
The continuous level measurement requires a radiation field across the whole measuring range. If the level rises within the range of the radiation field, the attenuation increases, and the detector measures less radiation. Therefore, level can be reliably monitored irrespective of vessel and product pressure, temperature, viscosity, color, and chemical properties.
There are different possibilities how a radiation field is formed. Either a rod detector or a rod source is used; sometimes it is most beneficial to use both in combination.

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Technology Highlights

Quality and safety

  • Comprehensive safety features
  • In-house production of various source types and shapes with different isotopes
  • Regular quality and stress tests
  • Quality made in Germany

Simple and intuitive operation

  • 2-wire systems with separate transmitters1 or compact probes2
  • Communication via HART, 4-20 mA, Profibus PA, Foundation Fieldbus
  • Robust design
  • Intuitive software solutions

1 2-wire systems with separate transmitters: 2-wire measuring system consisting of detector and transmitter, in which the transmitter is housed in the control room.
2 Integrated systems: detector integrated with transmitter which is operated via HART or bus communication.Compact probe: detector with integrated evaluation unit, which is operated via HART or bus communication.

Up to 8 m measuring range with one detector

The TowerSENS with a maximum sensitive length of 8 m is an extremely efficient solution for long measuring ranges. The TowerSENS detector ensures high sensitivity and accuracy over the whole measuring range.

TowerSENS Detector

Highly sensitive measurement systems

When compared to our comptetitors, our detectors with industry leading sensitivity achieve better accuracy with the same source, or can extend the useful life of aged and low activity sources. Depending on the application, the source activity can be reduced by up to 80 %.

More about sensitivity

Detector stability in continuous level measurements

The longterm stability of a detector is extremely important for consistent high quality measurement performance and accuracy during the many years of operation. Longterm drifts of detector sensitivity can be caused by temperature changes and aging. If they go unnoticed and are not compensated, they can cause a considerable loss in production yields and product quality suffers. See how our detectors maintain industry leading longterm 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 signals the detection of interfering radiation.
All of our level measurement detectors are equipped with XIP.

More about XIP

Product Radiation Compensation (PRC)

Does your product contain natural radioactive radiation? No problem!
The Product Radiation Compensation (PRC) independently measures gamma from the product and removes its effect upon the measurement, for a reliable accurate level measurement.

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Gas Property Compensation (GPC)

Gas property fluctuations in large vessels can greatly impact the amount of gamma at the detector, and therefore impact the measured value, if Berthold's gas property compensation is not added. With GPC, a second detector monitors how much the gas properties are effecting gamma transmission. Based on this, the level detector compensates for changes in gas properties, providing a reliable level measurement.

More about GPC


 DuoSeries LB 470SENSseries LB 480


 DuoSeries LB 470SENSseries LB 480
Intrinsically safe signal output  
Intrinsically safe power supply  
US/Canada (FM / CSA)  
SIL 2/3  
 DuoSeries LB 4700SENSseries LB 480
 DuoSeries LB 470SENSseries LB 480
X-Ray Interference Protection  
Monitored current output  
Gas Property Compensation GPC  
Quick start  
(compensation for products with natural radioactivity)
Speedstar (50 ms response time)  


 DuoSeries LB 470SENSseries LB 480
Separate transmitter  
HART communicator  
DeltaV AMS / Simatic PDM  


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