Loading errors in cone-plate rheometry

Abstract

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.

Quantifying the errors due to overfilling for Newtonian fluids in rotational rheometry

“…Giles and Hooper (1999) presented results showing that the effects of overfilling on the generated torque values in a rotational rheometer depend on the amount of overfilling, as well as on the ratio of gap spacing to plate diameter. Davies (2015) demonstrates that the viscosity measured with a cone-plate rheometer is less sensitive to overfilling as compared to underfilling. Nevertheless, this source of experimental error cannot just be taken for granted or ignored.…”

“…The analysis performed here is applicable for sample overfilling. However, it is known that sample underfilling leads to a viscosity value that is lower than the true value (Davies 2015;Hellström et al 2015). In the case of symmetric underfilling, the correct viscosity value can be obtained by taking into account that the generated torque only originates from the part of the geometry that is wetted by the sample.…”

Evaluating medical device and material thrombosis under flow: current and emerging technologies

“…194 Additionally, the rheological data are influenced heavily by the utilised geometries and are susceptible to user errors caused by incorrect blood sample loading such as underfilling or overfilling and the inclusion of trapped air and air bubbles. 64,[195][196][197]…”