An intercomparison of mass standards of 50g and 10g has been carried out. All the experimental work is now complete; the only outstanding work is the finalisation of the publication of results.
The intercomparison consisted of a series of bilateral comparisons between the pilot laboratory (NPL) and each participant. This enabled mass measurement techniques and weighing schemes to be compared, as well as mass values. To minimise the effects of possible instability of the transfer standards, they were carefully selected and closely monitored by the pilot laboratory throughout the measurement program. All participants made a reciprocal visit to NPL with one pair of their own standards which enabled the same comparative measurements to be made at both laboratories. The results of all four laboratories showed good agreement, better than 3 microg at 10 g and 8 microg at 50 g.
A meeting of the participants was held at PTB on 24 November 1989 to discuss the draft reports and the form of publication of the results. The main report will be submitted for open publication shortly. Each participant is individually publishing a report.