Loading errors in cone-plate rheometry

Errors arising from the under- and overfilling of cone-plate geometries have been investigated for combinations of smooth and micro-roughened cone-plate geometries. We observed experimentally that 0.1 ml deviations in the loading volume, such as can occur due to subjective filling or evaporation, will proportionally change the measured viscosity by 2–3%. We also give a simple method to avoid these errors during routine measurements.