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State of the art measurement technology

Density measurement system installed on pipeline

Density measuring principle by Berthold!

The radiometric measurement of density is based on the Gamma transmission principle. Gamma radiation is attenuated as it passes through a pipeline. The extent to which the radiation is attenuated is dependent on the density of the medium in the pipeline. The higher the density, the less radiation reaches the detector. In this way, density, concentration and solids content can be determined reliably with no contact – regardless of pressure, temperature, viscosity, conductivity and chemical properties. This results in high reliability and low maintenance, even under severe operating and environmental conditions.

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Technological Highlights

Simple and intuitive operation

  • Independent of the physical properties of the material being measured
  • Easy installation, on the outside of the pipeline
  • No changes to the piping required
  • No contact with the material being measured

Quality and safety

  • No wear and maintenance-free - high availability and thus high operational reliability
  • In-house production of various point and rod sources with different isotopes
  • [SIL2] [SIL3] [EX] TÜV Süd certified
  • Long-term stable measurement without recalibration
  • Worldwide sales and on-site service from the leading manufacturer of radiometric measurement technology

Measuring principle & function

Flexible adjustments for your density measurement task

Offering multiple detectors and sources enables customized solutions that perfectly meet your requirements. Detectors and sources can be combined in various ways and may also be inserted in dip pipes. Regardless of the measuring configuration and component aging, all systems can compensate for fluctuating temperatures, which guarantees the highest level of accuracy. Berthold's custom solution depends on the measurement geometry, accuracy requirements, and electronic preferences.

Density measurement

90° irradiation

Standard solution

  • Ideal for medium and large pipe diameters
  • Easy installation due to preassembled  mounting device

Density measurement

30° or 45° oblique irradiation

Used if attenuation with 90° irradiation is not sufficient

  • For small pipes
  • For small measuring ranges
  • Easy installation due to preassembled mounting device

Density measurement

S- or U-shaped measuring path

Used if 30° irradiation is not sufficient

  • For very small pipes
  • For extremely fine measuring ranges
  • Easy installation due to preassembled mounting device

Components used for density measurement purposes

Point sources

Point sources are widely used in many measurement tasks, including density, continuous level, and level switch. The compact nuclear source is enclosed in a capsule, and held in a shield with a shutter mechanism. The shutter allows the gamma to be directed towards the detector while the measurement is in use, or blocks it so that the source can be locked out when the vessel or pipe must be accessed, when not in use, and for storage and transportation purposes. More information

Point detectors

Detectors with a small scintillator are called point detectors. They often employ a short cylinder as scintillator, e.g. 50 mm diameter and 50 mm in length. They are typically used for density and level switch applications but can also be used for continuous level measurements. Depending on the measurement task and required sensitivity, other scintillator sizes may be used. Due to the small sensitive area, point detectors are not greatly affected by background radiation. Additionally, point detectors can be easily equipped with a lead collimator to further suppress background radiation.

Highly sensitive measurement systems

Berthold detectors have industry leading sensitivity. This offers the following advantages:

  • Increased measurement accuracy and faster response times
  • High long-term stability and measured value reproducibility
  • Significantly lower source activity
  • Longer useful lifetime for existing sources when retrofitted with Berthold detectors 
  • Use of smaller shields and thus lower costs
  • Minimum dose rate - less than 1 μSv/h

More about sensitivity

Unique long-term detector stability

A stable and reliable measurement over many years is an important quality criterion when choosing a radiometric density measurement system. Accordingly, much effort has gone into the development and optimization of Berthold detector stability. We are proud to say that Berthold detectors offer the best long-term stability. A patented automatic drift compensation method compensates for temperature and aging effects, ensuring high sensitivity and consistent measurement accuracy over the life of the system, and years of operation without recalibration.

Pages of Whitepaper radiometric measurement

Whitepaper "Radiometric Measurements"

A whitepaper explaining how radiometric measurements work and the components, as well as how they can be optimized for the highest accuracy and reproducibility. The paper explains best practices and how proper design minimizes error.

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Publication Made to measure in Hydrocarbon Engineering

Article "Made to measure"

Do you need reliable control of your fluid catalytic cracking (FCC) process, but the extreme process conditions are beyond the limitaitons of standard measurement technologies? Read the article “Made to measure” to learn why the use of radiometric measurement systems can help to optimize level control in FCC units, and how Berthold systems can help you to control your process more reliably to ensure safe operation while increasing efficiency.


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