The equivalence in accreditation: Robust or standard statistical analysis of interlaboratory comparisons

Interlaboratory comparison (ILC) have been carried out between accredited laboratories, to improve confidence in the comparability of the measurements results obtained in different regions. In the EA framework, about 120 ILC in the different calibration field (acceleration, acoustic, electrical, force, torque, hardness, frequency, photometry, pressure, chemical analysis, etc.) were performed in the last eight years, with several thousand of Calibration Laboratories involved in these exercises. In the paper, a short synthesis of the results obtained in the APLAC-ILC Rockwell hardness test (T027) is given as an example, and compared with the results obtained in a analogous intercomparison in the EA framework (ILC-H1).