Press ENTER to search or ESC to close

DK 18/26 Digestion Unit

Kjeldahl Digestion Units with 18-position aluminum heating block that offers an excellent thermal homogeneity for micro-kjeldahl applications. 
Contact a specialist Find a dealer
Add to favorites
DK 18/26F30100430
DK 18/26 Digester SystemS30100430
DK 18/26F30110430
DK 18/26 Digester SystemS30110430

Thermal homogeneity and precision

Thermal homogeneity and precision
The DK 18/26 Series digestion unit with aluminum heating block ensures high thermal homogeneity heating up to 450 °C. The temperature of the block is constantly controlled by a microprocessor and is extremely stable, homogeneous and precise: ±0.5°C at all selectable temperatures.

The DK 18/26 Series guarantees accuracy and repeatability. The DK 18/26 performs batch digestion of up to 18 samples with 100 ml test tubes - Ø 26 mmreducing the energy consumption (-13% compared to the previous series). Low energy consumption provides lower costs of analysis and limits CO2 release.

Space saving design

Space saving design
The design of the DK series has been carefully engineered to allow laboratories to save valuable space under the hood.

DK Digesters have very compact dimensions: the new aluminum heating block has been lowered and the vertical proportions allow to free precious space in the laboratory.

The structure is made of stainless steel that has been specifically designed and tested to ensure strong resistance to chemicals and mechanical stress.

The aluminum block protection grid provides enhanced heating performance and protects the heating block from splashes and chemicals.

Easy-to-use with the intuitive digital interface

Easy-to-use with the intuitive digital interface
The bright digital display provides maximum visibility and easy-to-read information.

The instrument is operated with 4 keys to navigate the menu options and program the digestions in a simple and fast way

Through the intuitive graphic display it is possible to set up to 20 methods with 4 temperature ramps. 

Acoustic signals inform the operator of the completion of the analysis facilitating the daily use of the digester.

The inclination of the front panel protects it from chemical spillage at high temperatures. 

Fume Neutralization System

Fume Neutralization System
For applications where the digestion process produces fumes, acid gases or corrosive substances, the below specific accessory is strongly recommended:
  • KS 1000 Scrubber neutralizes all the fumes

TEMS™ Technology

TEMS™ Technology
DK Series Kjeldahl digestion units work with the innovative TEMS™ benefits, for huge savings.

Time Saving: rapid heating reduces wasted time
Energy Saving: limited energy consumption thus cutting CO2 emissions
Money Saving: cost reduction for each analysis
Space Saving: the narrow footprint saves valuable laboratory bench space


Please select the model:

cod. {{::variant.code}}
* {{::variant.shipment}}
${{::variant.promoPrice ? variant.promoPrice : variant.price | format}} ${{::variant.price | format}}

cod. {{accessory.code}}

cod. {{accessory.code}}
${{accessory.promoPrice ? accessory.promoPrice : accessory.price | format}} ${{accessory.price | format}}

cod. {{accessory.code}}
${{accessory.promoPrice ? accessory.promoPrice : accessory.price | format}} ${{accessory.price | format}}
Included/required accessories: {{(includedAccessories ? includedAccessories.accessories.length : 0) + (requiredAccessories ? requiredAccessories.accessories.length : 0)}} (${{requiredAccessoriesPrice | format}})
Optional accessories: {{optionAccessoriesCount}} (${{optionalAccessoriesPrice | format}})
Add to cart
Request a quote
Included/required accessories: {{(includedAccessories ? includedAccessories.accessories.length : 0) + (requiredAccessories ? requiredAccessories.accessories.length : 0)}} (${{requiredAccessoriesPrice | format}})
Optional accessories: {{optionAccessoriesCount}} (${{optionalAccessoriesPrice | format}})
Add to cart
Request a quote

Genuine consumables for your digestions

Genuine consumables for your digestions
Choosing the right consumables allow the optimization of analytical operations to achieve the highest possible performance of your Digestion Unit. We strongly recommend the use of VELP original consumables in order to be sure to obtain the best performance form your VELP instrument. 

The addition of a suitable catalyst, along with high temperature, have influence on the speed and the efficiency of the mineralization in Kjeldahl analysis. Achieving the highest level of performance in a wide range of Kjeldahl applications is now possible with VELP genuine KjTabs™ catalyst and antifoaming tablets.

VELP Nitrogen Free Weighing Boats are the perfect solution to all the difficult transfer operations of powders or syrupy samples into mineralization test tubes.


Construction material: Epoxy painted with chemical resistant coating
Temperature range: Ambient to 450 °C / 842 °F
Stability of the heating block temperature: ± 0,5 °C
Precision of the heating block temperature: ± 0,5 °C
Set temperature: Digital readout in °C or °F
Temperature Calibration: Automatic
Selectable ramps: up to 4 per program
Digestion time range: 1 to 999 minutes
Time selection: 1 minute steps
Countdown: Digital readout
Selectable language: EN, IT
Heating Places 18-position
Size of tubes 100 ml test tubes (Ø 26 mm)
Power: 1150 W
Dimensions (WxHxD):
(aluminum block only)
230x140x420 mm
9.1x5.5x16.5 in
Dimensions (WxHxD): 230x690x420 mm
9.1x17.2x16.5 in
Weight: 11 kg (24.2 lb)

Brochures & Leaflets

VELP Scientifica invites you to download brochures and leaflets in order to explore our premium quality solutions and to have all the major key arguments, features and specifications of a product in your hands, in any place, and at any time.

Comparison tables

Select the category of products you are interested in and this tool will give you an easy overview of what is available at VELP in order to find the product that is perfect for you. These comparison tables provide a brief description with side by side features from basic equipment to the most advanced analytical solutions.

Application notes

Choose among a comprehensive library of Application Notes / White Papers and learn more on how to optimize the performance of your VELP instruments. These documents offer typical analyses of well-known samples, together with official references and suggestions, to make you an expert!


Our compliance to statutory rules and regulations worldwide.
With the CE mark, VELP Scientifica declares that the products are designed and manufactured in compliance with the essential safety requirements of the European Directive on Safety.
The Certification Body (CB) Certificate is an international program created by the IECEE for the acceptance of product safety test results among participating laboratories and certification organizations around the world.
The cNEMKOus mark ensures this product is designed and manufactured in compliance with the International Directive on Safety IEC/EN 61010-1. The cNEMKOus mark has the same legal status as any other NRTL/SCC accredited marks, for U.S. and Canada.
Service offering
Close to our customers: we are committed to supporting you anytime, anywhere
Check technical sheets with answers to most frequently asked questions
What do we have to add to the test tube to perform the digestion step?
To properly perform the digestion step, it is necessary to prepare the glass test tube with the sample and:

1. KjTabs™ catalyst tablets to accelerate the digestion
2. Antifoam tables (especially recommended in the case of samples with a high-fat content)
3. 12 - 15 ml of concentrated sulfuric acid (98%)
How to insert the sample into the test tube?
The sample must be weighed within Nitrogen free weighing boats (CM0486000) and then placed inside the test tubes. In so doing there is no risk of part of the sample sticking to the test tube parts and the digestion therefore not being performed correctly.
Which kind of test tubes does VELP supply?
VELP provides a full set of test tubes. Download here the comparison table!
For which applications should Micro-Kjeldahl tubes be used?
The Micro Kjeldahl tubes can be used if the compound is homogeneous and small samples are fully representative, or if it is specified by an approved method (AOAC method 960.52, Microchemical determination of Nitrogen). Note that the Micro-Kjeldahl method requires smaller volumes of chemical reagents. 

Micro Kjeldahl units are also used to perform the step of nitrogen content determination during the dietary fiber extraction process. 
Siglacom - Internet Partner