First density comparison on viscoelastic samples by oscillation-type densimetry

Abstract

To provide a deeper insight about the damping effects produced by the viscoelasticity of non- Newtonian fluids during density measurements with oscillation-type density meters, and about how reference laboratories overcome these effects, an international comparison was performed, within the scope of the EMPIR Project 17RPT02 rhoLiq. The results of the comparison evidenced the possibility to measure density of viscoelastic samples by means of oscillation-type density meters with an uncertainty between 0.10 kg·m<sup>-3</sup> and 0.25 kg·m<sup>-3</sup>. However, these instruments may be able to reach lower uncertainties if compared with higher precision density measurement methods such as hydrostatic weighing.

Introductory notes for the Acta IMEKO fourth issue 2023

“…For this purpose, the surface tension of 6 liquids, was determined at 20 °C, using force tensiometers, with 2 different measuring probes (Du Noüy ring and Wilhelmy plate), and by applying different correction factors. The results presented in [9] allowed the Authors to conclude on the degree of equivalence of surface tension measurement results, obtained by each NMI, by using different probes and measurement models.…”

“…In [9] the lack of intercomparisons in surface tension measurements, and the need to establish the degree of equivalence of such measurements are considered. These needs have led to a comparative study on this subject carried out by 3 National Metrology Institutes (from Poland, Portugal, and Turkey), within the scope of the Project 17RPT02-rhoLiq.…”