A comparison of gauge blocks has been carried out in the Asia/Pacific
Region as part of an international comparison decided on by the Comite
Consultatif pour la Definition du Metre. Ten national standards labor
atories measured a set of five grade 00 gauge blocks (and two replacem
ents) using interferometry. This paper reports on the comparison and s
hows that for gauge block lengths up to 40 mm (original set) all labor
atories agreed to within +/- 0,03 mu m and for the 100 mm gauge block
they agreed to within +/- 0,08 mu m.