Inmetro's a performance in calibration off ball bars

5 f. : il.The Dimensional Metrology Laboratory of the National Institute of Metrology, Standardization and Industrial Quality (LAMIN /INMETRO) has implemented a measuring system for calibration of length standards by adapting a linear interferometric laser to a coordinate measuring machine (CMM). This measuring system has shown to be efficient,through the association of the interferometric laser high accuracy to the high displacement versatility of the CMM, obtained by a numeric control program. With this system, the measuring uncertainties can be considerably reduced, when compared to those obtained exclusively with the CMM. This measuring system was evaluated through a laboratorial comparison with the national German institute “Physikalisch-Technische Bundesanstalt” - PTB, involving the calibration of two steel and one Aluminium ball bars, used as reference in the coordinate measuring technique. The comparison results have proved to be compatible, assuming the technical competence of the Dimensional Metrology Laboratory to provide traceability to accredited laboratories by the Brazilian calibration service (RBC) and by the German calibration service (DKD) in Brazil, as well as to other laboratories installed in the countries which take part of the MERCOSUL