Some important characteristics of gauge-block artefacts for international comparison

This letter takes a brief look at gauge-block length as it is influenced to a subtle degree by the surface quality of the measuring face and the recen t history of the gauge block environment. Change in length of short gauge b locks following wringing, and of long gauge blocks. following air travel be tween laboratories, is demonstrated. These effects could have important imp lications for international comparison testing under time-limited condition s, particularly with the large number of comparisons related to the Mutual Recognition Arrangement (MRA).