>>I just don't know if the measurements made by a trained scientist and those made by the average beekeeper would be of comparable accuracy.

This is a mechanical measurement; you don't need a scientific background.  I use calibrated calipers (I have a set of jo blocks certified to several millionths of an inch to verify my measurement tools) that increments .001 in. (or 0.025 mm).  I worked as an inspector of optical and mechanical parts when I was in college.  If it means anything, a Swiss parts supplier used to say 'Waldemar ist sehr genau!' and the Swiss excel in accuracy.  

Waldemar

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