Interlaboratory comparisons for frequency calibration: A first two-year campaign in Italy

In 2011 and 2012, ACCREDIA DT (the Calibration Laboratories Department of the Italian accreditation body) and the Time and Frequency Laboratory of the Istituto Nazionale di Ricerca Metrologica (INRIM) organized two Interlaboratory Comparisons for the Italian Accredited Calibration Laboratories, aiming to experimentally assess their calibration measurements capabilities (CMC). Two sets of instruments, preliminarily calibrated by INRIM, were circulated among the laboratories following a multi-lateral scheme with INRIM acting as pilot laboratory. The measurement results and an overall critical assessment of this exercise is provided and suggestions on possible improvements are discussed.