A4.2 - Novel Sensor Principle for High-Precision SI-Traceable Force Measurements
- Event
- SMSI 2025
2025-05-06 - 2025-05-08
Nürnberg - Band
- Lectures
- Chapter
- A4 - Revised SI
- Author(s)
- M. Wittke, M. Torres Melgarejo, M. Wolf, R. Theska, T. Fröhlich - Technische Universität Ilmenau, Ilmenau (Germany)
- Pages
- 51 - 52
- DOI
- 10.5162/SMSI2025/A4.2
- ISBN
- 978-3-910600-06-5
- Price
- free
Abstract
Prior to 2019, force and mass measurements had to be traced back to the International Prototype Kilogram, which realized the SI unit kilogram. This definition required a long calibration chain with a series of relative mass compar-isons. By setting Planck's constant to a fixed numerical value of h = 6.626 070 15 · 10-34 J s in the redefinition pro-cess, each instance of the calibration chain can now traceably measure absolute forces or masses. However, sys-tems that provide a direct correlation between electrical and mechanical quantities are required. This work presents a novel sensor principle for high-precision SI-traceable force measurements. The sensor is based on the Planck Balance principle. Sub-mechanisms for compensating the stiffness of the compliant kinematic structure are inte-grated to maximize the resolution and minimize the uncertainty. The compensation mechanisms are based on preloaded springs to guarantee functionality in any orientation. The stiffness can be reduced to at least 0.04 % of the initial value. A force resolution below 40 pN is therefore achieved.