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2023 Proficiency Test (PT) on Hydraulic Oil (used) started


The letter of instructions can be downloaded here as a pdf document. To download a document, please click the right mouse button and choose the "save as" option.


Please download the instructions for the PT iis23L10 here: the letter of instructions and the report form here

Download the instuctions for iis23L10M here: letter of instructions for Metals and the report form here


Summary of this proficiency test:


On 11 October 2023 the proficiency test on Hydraulic Oil (used) started with 61 participants from 38 different countries. On that date, the samples were dispatched to the laboratories. Enclosed to the sample is the material safety data sheet (MSDS).

Please confirm sample receipt as soon as you have received and checked the contents of the sample package via Please enter the date of receipt and press the "save date" button.


The samples can be analyzed on: Total Acid Number, Density at 15°C, Flash Point PMcc, Kinematic viscosity at 40°C / 100°C, Viscosity Stabinger at 40°C / 100°C, Sulfur, Water, Level of Contamination, Al, Ba, B, Cd, Cr, Cu, Fe, Pb, Li, Mg, Mn, Mo, Ni, K, Si, Ag, Na, Sn, Ti, V, Ca, P and Zn. 


The deadline for reporting results is set on 17 November 2023. A laboratory that reports test results after the deadline will definitely not get direct feedback in case any of its results are suspect! So be in good time to get the most out of this proficiency test.

The test results should be reported via our internet based results reporting platform A login and a password can be requested via email to





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