The Magnetic Suspension Balance – 40 Years of Advancing Densimetry and Sorption Science Xiaoxian Yang1, Reiner Kleinrahm2, Mark O. McLinden3, Markus Richter1,

Published

November 7, 2023

Author(s)

Xiaoxian Yang, Reiner Kleinrahm, Mark O. McLinden, Markus Richter

Abstract

This paper reviews the 40-year evolution and application of the magnetic-suspension balance (MSB) and discusses some challenging issues of the technique. A MSB, as we define it here, is a magnetic-suspension coupling (MSC) connected with an analytical balance. With a MSC, an object can be weighed in a different environment than the balance itself, making it possible for contactless weighing. Over the past 40 years, the MSB has been commonly used in research areas requiring accurate sample weighings, notably gas density measurements by MSB-based densimeters and gas-adsorption measurements by MSB-based sorption analyzers. More than 15 MSB-based densimeters have been built to date; these are generally called two-sinker densimeter and single-sinker densimeter. They have produced highly-accurate density data of many pure fluids and fluid mixtures. These data serve as a basis for the development of reference equations of state, which play essential roles in various industrial and scientific areas. Moreover, such systems are central to the metrology program of many countries. The MSB technique is also very successful in adsorption science: more than 85 MSB-based sorption analyzers have been set up over 20 countries. The number of new MSB-based sorption analyzers, and peer-reviewed publications resulting from them, are both increasing exponentially since 2004. They have produced highly reliable gas adsorption data at high pressures for many applications, mainly in the energy and environment sectors. Although continued development of innovative instruments built up around MSB is threatened by the proprietary nature of MSB technology, the development is still ongoing, for example, towards cryogenic measurements and a more compact design.

Citation

International Journal of Thermophysics

Pub Type

Journals

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Keywords

review, magnetic-suspension balance, densimeter, sorption analyzer

Citation

Yang, X. , Kleinrahm, R. , McLinden, M. and Richter, M. (2023), The Magnetic Suspension Balance – 40 Years of Advancing Densimetry and Sorption Science Xiaoxian Yang1, Reiner Kleinrahm2, Mark O. McLinden3, Markus Richter1,, International Journal of Thermophysics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956208 (Accessed May 1, 2024)