The statistical evaluation of the interlaboratory comparison is defined in ISO 13528 and ISO 5725-2.

148 testing laboratories from 35 countries all over the world participated in 66 individual test methods in the last proficiency test OFI-pts2020.

Argentina Malaysia
Austria Marocco
Belgium Norway
Bulgaria Poland
Canada Portugal
China Romania
Croatia Slovakia
Czech Republic Slovenia
Finland South Korea
France Sri Lanka
Germany Spain
Great Britain Sweden
Greece Switzerland
Hungary The Netherlands
Israel Turkey
Italy Thailand
Japan  USA
Lativia  


Evaluation parameter

Outlier according to Grubbs’ test
Outlier according to Cochran’s test
z-score
Youden-Plot (Scatter diagram)