Lab instruments for oil and gas. Made in Germany.

Coaxial-Shear Cold Finger cCF6 - the specialist with rotating fingers

Measure wax deposits under shear conditions

The laboratory device of the Coaxial-Shear Cold Finger cCF6 examines wax deposits and the effectiveness of wax and parrafin inhibitors. The 6 measuring stations in a water bath available for this purpose. All fingers can rotate to  measure the wax deposition under shear conditions.

All the important features and areas of application of the Coaxial-Shear Cold Finger cCF6


  • Convincing improved handling
  • Precise finger and bottle positioning for accurate results
  • Removable sleeves for easy weighing and cleaning
  • 6 measuring places forsimultaneous tests


  • Low to medium sample volume for cold finger measurements
  • For sample tempering up to 90 °C
  • Examine wax content and paraffin deposition
  • Determine the Wax Appearance Temperature (WAT)
  • Development and optimization of wax and paraffin inhibitors

The short story - What makes the Coaxial-Shear Cold Finger unique?

With the Coaxial-Shear Cold Finger cCF6, the classic design of the Multi-Place Cold Finger CF6 with water bath is extended to include shearing. For users, this means greater convenience in handling and more accurate results.

Based on the proven PSL cold finger measuring technology and a new type of lift system, the 6 sample units are held separately from each other. This means that different chemicals or sample concentrations can be measured in parallel and the samples can also be individually pre-tempered. The cooling fingers can be positioned to match the size of the sample bottle in order to measure the temperature exactly where the wax deposits occur.

The CF6 has been designed to be easy to use and to need a small space in the laboratory.

The removable sleeves allow the measurement of wax deposits over time as well as easy weighing and cleaning.

The almost closed water bath significantly minimizes the evaporation of the bath liquid, so that measurements up to 80 °C are easily possible and even temperatures up to 90 °C are realistic. For greater safety and to prevent condensation, the water bath and all hoses are insulated.

Measurement Principle

A crude oil sample is stirred and kept above Wax Appearance Temperature (WAT). A cooled zylinder element - so called 'cold finger' – is immersed in the sample, providing a cold surface, where the waxes of the crude oil shall deposit. An integrated magnetic stirrer is providing a gentle circulation to ensure that all of the sample gets in touch with the cold finger surface. The amount of wax that deposits at this surface at given temperature in ratio to the total amount of sample is an indication of potential amount of wax deposition as well as, related to a blank test, for the efficiency of a wax inhibitor (WI). Different then with a 'classical' Cold Finger, a well-defined shear can be applied to the finger surface by rotation of the finger. By use of different rotation speeds the shear condition that applies during production on the pipeline wall can be simulated. 

Test Procedure

The Coaxial-Shear Cold Finger cCF6 is designed as a very compact instrument combining 6 fingers integrated in one drive block in the head section. The sample bottles are screwed in the block and immersed with a pneumatic lift into a temperature controlled water bath. At the end of the experiment the head section is lifted again and the bottles are removed. To measure the amount of wax deposition the well-fitting measurement sleeves are removed from the fingers and then weighed on a balance. 

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