In 2017, the third edition of ISO/IEC 17025 standard was completed. This version will cancel and replace the second edition from 2005, which has been technically revised. Even if, in the second version, maintaining confidence in the calibration status of standards through intermediate checks was not clearly explained in terms of a procedure (referring to this term only in subchapters 5.5.10, 5.6.3.3 and indirectly in 5.9.1), nor in the new version of the standard this subject is not detailed. It is up to each laboratory to carry out these checks according to defined procedures and schedules as well establishing the acceptance criterion. So, the questions arising about performing intermediate checks are: when, where, how? The paper presents different approaches regarding intermediate checks performed in the field of mass measurements: in the calibration/verification of weights, of mass comparators and NAWI (non automatic weighing instruments). In the case of NAWI, considering the laboratory's scope of accreditation, the evaluation method is presented in different ways.
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