Rod sources

Best measurement accuracy!

Our custom-made rod sources have the radioactive material distributed along the entire source length tailored upon the application, vessel geometry, and detector. Compared to a point source, the individual activity distribution improves the linearity of the measured count rate at the detector to the level in the vessel for continuous level measurements and ensures the highest accuracy with the simplest calibration.
With our unique manufacturing technology, the radioactive material is distributed along an inner guiding rod within a tightly sealed outer capsule. In a rod source / point detector arrangement, the radioactive material in the rod source is higher concentrated in the lower part of the rod, which intensifies the activity in this area. This is advantageous because due to the increasing distance to the detector, which is usually mounted at the top, the travel distance of the gamma radiation increases, as well as the radiation must pass through the vessel walls at a smaller angle. This increases the effective wall thickness and thus the absorption. A higher activity in the lower part of the rod source compensates for this effect.

Why are rod sources often the technically better solution?


  • If the calibration of the measurement should preferably be as simple as possible
  • If the measured value has to be stable, accurate and reproducible over the entire lifetime of the measurement, without recalibration
  • If process influences such as gas density fluctuations or wall build-ups are to have as little influence as possible on the measurement
  • If non-destructive testing of welds are performed frequently
  • If spare parts inventory should be uncomplicated
  • If production downtimes must be kept to a minimum in the event of a detector defect


Whitepaper "Rod source / point detector"

Long-lasting process quality due to advantageous measuring arrangement

Advantages and preconceptions of a rod source/point detector arrangement

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Berthold Webinar

Rod Sources – A Game Changer for Radiometric Measurements?

In this webinar OUR EXPERTS from Berthold show you the advantages of a rod source / point detector arrangement. They will explain what makes this combination the superior solution for most level and belt scale measurement tasks.

Watch now

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

Radiation Interference Discrimination (RID)

DuoSeries LB 470 is now also available with radiation interference discrimination (RID). The level measurement system with RID consists of a Co-60 source,  an LB 4700 detector with PVT scintillator, and a separate LB 470 RID transmitter for display, calculation. The detector mounted at the measuring point is connected to the LB 470 RID transmitter via a two-wire cable. If you want to continue measuring despite impending external radiation, then the LB 470 RID version is the right choice. 

More about RID


We are committed to the ALARA principle. ALARA stands for: As Low As Reasonably Achievable and aims to keep the source size to a minimum.

In accordance with this principle, we select source activity specifically for your application based on the process data and measurement requirements.

Due to our highly sensitive detectors, we are able to use very low source activities while maintaining measurement accuracy and reliability. 

Benefit from our safety awareness, custom solutions, and the reduced cost for shielding and transportation.