State of the art measurement technology

Level measurement system installed on vessel

Continuous level measuring principle by Berthold!

Gamma radiation, emitted from a shielded source is attenuated as it passes through the vessel. This attenuation is measured by a highly sensitive detector, mounted at the opposite side of the vessel. As type of radiation and measuring geometry are constant the attenuation will only be affected by a change in level.
The continuous measurement of level uses a radiation field over the whole measuring range. If the level rises within the range of the radiation field, the attenuation becomes stronger and consequently the detector measures less radiation. In this manner, the level can be reliably monitored - irrespective of pressure, temperature, viscosity, color and all 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.

Learn more

Technological 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

Simply and intuitive operation

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

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

Long measuring ranges up to 8 m

The TowerSENS with a max. length of 8 m is an extremily efficient solution for very long measuring ranges. Nonetheless, the TowerSENS detector ensures high sensitivity and accuracy over the whole measuring range.

TowerSENS Detector

Highly sensitive measurement systems

Our high-sensitive detectors achieve a better measuring effect and can work with remarkably low source activities. 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 a consistently high quality measurement performance and accuracy during the entire 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.

X-ray Interference Protection (XIP)

With this function, weld tests can no longer distort the measured value. The measured value is frozen until the external radiation influence is over. A digital output signals the detection of interfering radiation. All our level measurements 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) feature provides reliable, accurate level measurement through independent activity measurement and integral compensation for a reliable and precise level measurement.

More about PRC

Gas Property Compensation (GPC)

In the case of radiometric measurement, gas density variations can falsify the measured value, unless you have gas density compensation from Berthold. With the feature GPC, a second measurement determines the current gas density in the tank and has a compensating effect on the connected level measurement. 

More about GPC


 DuoSeries LB 470SENSseries LB 480Uni-Probe LB 490
Foundation Fieldbus / Profibus PA   


 DuoSeries LB 470SENSseries LB 480Uni-Probe LB 490
Intrinsically safe signal output   
Intrinsically safe power supply   
US/Canada (FM / CSA)   
SIL 2/3   
 DuoSeries LB 470SENSseries LB 480Uni-Probe LB 490
 DuoSeries LB 470SENSseries LB 480Uni-Probe LB 490
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 480Uni-Probe LB 490
Separate transmitter   
HART communicator   
DeltaV AMS / Simatic PDM   


Continuous Level Measurement Product brochure

English | PDF | 4.9 MB

Radiometric measurement Whitepaper

English | PDF | 1.8 MB

Radiation Interference Discrimination (RID) Whitepaper

English | PDF | 1.5 MB

Article made to measure Publication

English | PDF | 6.8 MB