Determination of the force transmission error in a single-sinker magnetic suspension densimeter due to the fluid-specific effect and its correction for use with gas mixtures containing oxygen

TL;DR

This paper investigates the magnetic effects on a single-sinker magnetic suspension densimeter used for gas mixture density measurements, determining an apparatus-specific correction constant through two methods, with the more reliable value obtained from oxygen measurements.

Contribution

It introduces two methods to determine the fluid-specific correction constant for the densimeter, improving measurement accuracy for gas mixtures containing oxygen.

Findings

The apparatus-specific constant from density data is 4.6×10⁻⁵.

The constant from oxygen measurements is 8.822×10⁻⁵.

The oxygen-based value is more reliable due to fewer limitations.

Abstract

Density measurements from single-sinker magnetic suspension densimeters need to be corrected to compensate for the magnetic effects of the measuring cell materials and the fluid on the coupling transmission system. While the magnetic effect of the densimeter materials can be easily determined, the fluid effect requires the calculation of an apparatus-specific constant, $\epsilon_{\rho}$. In this work, the apparatus-specific constant of the single-sinker magnetic suspension densimeter at the University of Valladolid has been determined by using two alternative methods. The first method, which uses density data for the same fluid and conditions and different sinkers, yielded a value of $\epsilon_{\rho}$ = $4.6\cdot10^{-5}$. The second method, obtained from measurements with pure oxygen, yielded a value of $\epsilon_{\rho}$ = $8.822\cdot10^{-5}$. The second value is considered as more reliable, as the first method presents inherent limitations in this case.