The Kjeldahl method KjelDigester reduces the block digestion process by up to two hours and meets the highest safety requirements. The high degree of automation is the perfect match to the KjelMaster System allowing for unprecedented sample throughput.


Highly efficient

  • Acceleration of the heating and cooling step, saving up to two hours
  • Direct transfer of the 20 position rack to the KjelSampler
  • Unattended operation by using automatic lift and delayed start time (K-449 only)
  • Programmable time / temperature profiles and full Scrubber K-415 control (K-449 only)

Safe and convenient

  • Improved sealing for effective transfer of harmful fumes
  • No user contact with hot samples due to automatic lift (K-449 only)
  • Convenient magnetic suction module fixation
  • Extended lifetime of block and accessories with protective drip tray


  • Compliant to official regulations like AOAC, ISO, EN
  • Accurate temperature control following the programmed profile
  • Reproducible digestion due to the improved thermal homogeneity

Expert Advice

What are differences between IR and block digesters?

Differences between IR and block digester

Differences between IR and block digesters.

What is the difference between the standard suction module and the suction module with condensate trap?

The standard suction module is mainly used for unproblematic and dry samples. The suction module with condensate trap is used for aqueous samples, to speed up the digestion process as it avoids backflow of the evaporated water into the sample. Hence the evaporation of water is faster and the boiling point is reached earlier, it also helps avoid cross-contamination of problematic samples.

What are the benefits of block digestion?

The block digesters surpass IR digesters in automation (lift) and in compliance with official regulations. The 20 position rack in the block digesters can be directly transferred to the KjelSampler K-376 and K-377 for fully automated determination and high sample throughput.

Why do block digesters need lower set temperatures during digestion than IR digesters?

Due to the direct heat transfer of the contact of block to sample tube, lower set temperatures are required to achieve the boiling temperature.

Is it possible to shorten the digestion process by adding H2O2 and Kjeldahl Tablets prior to heating?

Yes, the time taken for metal salt catalyzed Kjeldahl digestions can be re­duced by up to 65 minutes (red vs. blue graph) by adding H2O2 together with Kjeldahl Tablets prior to digestion, as this combination speeds up the oxidizing process.

Degree of automation

Two models are available:

The fully automated model K-449 offers a convenient automatic lift and a programming mode for 9 digestion methods.
The manual K-446 is an entry level block digester with effortless manual control and manual rack handling.


Suction module types

Two dedicated suction modules can be selected; one for aqueous samples, and the other a standard suction module appropriate for general applications.

P: 1300 552 003