Seven national metrology institutes comprised of European and non-European member states participated in
the implementation of the first international comparison of involute gear standards. Participants include:
Germany, China, Japan, Thailand, United Kingdom, Ukraine and USA. This comparison was organized by
the European Association of National Metrology Institutes (EURAMET). The German metrology institute
Physikalisch-Technische Bundesanstalt (PTB) was chosen as the pilot laboratory as well as the
organiser.” Threetypical involute gear standards donated by the PTB were deployed for this comparison,
namely: profile-, helix- and pitch-standard. In the final analysis of the results obtained from all participants, the
weighted mean was evaluated as reference value from all 28 measured parameters. Consequently,
competency of each participant was estimated by calculating the normalized error En. The approach used
involves evaluating the compatibility of the obtained results taking into account their measurement
uncertainties. However, large distribution of the results that conform with range of today’s required tolerances
in industry pose a lot of questions. This presentation would present the measurement setup, the measured
parameters, and most importantly the comparison results from all participants which are anonymously
represented. Furthermore, mishandling of standards as experienced during the comparison would be
illustrated.