Our paper presents the motives for conducting the equivalence tests and the reasons of discrepancies between the results of PM₁₀ dust concentration obtained via the reference method and the methods based on ‘on-site’ measurement. The reference and non-reference methods of measurement of PM₁₀ dust concentration in air have been discussed. Field tests for equivalence, following the Polish standard and the European Union (EU) guidelines, carried out by the ARMAAG Foundation in the Tri-City region, have been analyzed. Correction factors with respect to the ‘on-site’ samplers, obtained in various measurement stations in the EU member countries, also are presented.