Abstract
Vane shear strength has played an extremely important role as an indicator of the burrowing
capabilities for diverse benthic organisms. For the purpose of simple measurement of the vane shear
strength and elimination of error by the measurer, we attempted automatic measurement of vane shear
strength by connecting a vane tester to a commercially available PET bottle opener. As a result of
comparing the measured values of the vane shear strength with manual measurement with gradients in
the particle size, density, and circularity of the substrate, the coefficient of determination in the regression
line of manual measurement was high in all cases, but there was no statistically significant difference
between them. The results of manual and automatic quantitative measurements also corresponded well
to the increase in the friction coefficient tanΦcalculated from the angle of repose of the substrate. These
results indicate the possibility of automating the measurement of vane shear strength by using a motor
with an appropriate range of starting torque.
