The statistical evaluation of the interlaboratory comparison is defined in ISO 13528 and ISO 5725-2.
157 testing laboratories from 35 countries all over the world participated in 68 individual test methods in the last proficiency test OFI-pts2019.
| Argentina | Japan |
| Australia | Jordan |
| Austria | Korea |
| Bangladesh | Lativia |
| Belgium | Malaysia |
| Bulgaria | Norway |
| China | Poland |
| Colombia | Romania |
| Croatia | Slovakia |
| Czech Republic | Slovenia |
| Finland | South Korea |
| France | Spain |
| Great Britain | Sweden |
| Greece | Switzerland |
| Hungary | The Netherlands |
| Iran | Turkey |
| Israel | USA |
| Italy |
Evaluation parameter
Outlier according to Grubbs’ test
Outlier according to Cochran’s test
z-score
Youden-Plot (Scatter diagram)
