Measurement of bulk density using the Archimedes method with an inductive spring balance
DOI:
https://doi.org/10.24425/mms.2025.155808Abstract
The article presents a new version of the hydrostatic method for determining bulk density. A spring balance was designed and constructed for measuring the bulk density of porous samples using the liquid displacement method (Archimedes’ principle). In the innovative spring balance, a weight-to-frequency converter based on an LC oscillator was used, in which the sensor consists of springs that simultaneously serve as the source of inductance in the oscillator’s resonant circuit. Changes in inductance caused by the variation in the spring length under the load of the weighed object result in a change in oscillation frequency. The spring balance design is characterized by great simplicity, and the converter has a high sensitivity at the level of 10-5. In this work, the bulk density of reference samples, both porous and non-porous, was investigated. The results of bulk density measurements for aluminium block and porous sandstone were compared with values obtained from professional pycnometers, namely, the helium AccuPyc 1340 and the quasi-liquid (powder) GeoPyc 1360 (Micromeritics Instrument Corporation, United States). The results confirm the full suitability of the spring balance for the intended purpose.References
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