INTERNATIONAL COMPARISON OF GAUGE BLOCKS UP TO 100 M LONG BETWEEN LATIN-AMERICAN COUNTRIES, SPAIN AND GERMANY

The paper presents the results of an international intercomparison of gauge blocks up to 100 mm in length, which was carried out in 1994/95 between twelve metrological laboratories in seven Latin American count ries, Spain and Germany and evaluated in 1996 on the occasion of a wor kshop in Brazil. Three identical sets of five selected gauge blocks of different lengths and calibration degree K were circulated between gr oups of 3 and 4 laboratories. Before and after each cycle, all gauge b locks were mechanically calibrated in the pilot laboratory ''Centro Es panol de Metrologia (GEM)'' in Madrid. Initial calibration was carried out in the PTB's laboratory for interferential length measurements, w hich acted as the reference laboratory. In the cours of the intercompa rison, the central length and the deviations from the central length w ere determined. On the whole, the results show good agreement with the PTB's reference values. In this contribution, the deviations of the r esults obtained by the individual laboratories are analyzed. The resul ts were discussed and evaluated at this workshop organized for all tho se who participated in the measurements. This enabled the metrology in stitutes of Latin America to assess the technical competence of their laboratories in the field of gauge block calibration. CEM cooperated a s rite coordinator in the intercomparison which was initiated by the P TB's ''Technical Cooperation'' department and financed by tile Federal Ministry for Economic Cooperation and Development (BMZ) within the sc ope of a supraregional project.