Quantum mechatronics in force measurement and weighing technology (QuMeT)

Prof. L. Zentner
Dipl.-Ing. A. Griebel

Mass comparators are currently the most accurate precision weighing systems for connecting mass standards to the definition of the unit kilogram (International Prototype of the Kilogram). They are necessary today and in the future to enable a precise mass standard for science and industry worldwide and mark the current limits of force measuring and weighing technology. Further increases in performance are essentially dependent on the reduction of the uncertainty of the electromagnetic force compensation (EMF) used in the comparators and on the entire system of force input, load alternator and measuring and control electronics.
More than two decades ago the limits of performance of mass comparators have been analyzed in the form of equal-arm beam scales, postulating an achievable relative standard deviation of 10^-12 for comparisons of 1kg mass normals. Nevertheless, there is no mass comparator to date that actually achieves this. An equal-arm beam balance built on BIPM and operating on the principle of electromagnetic force compensation achieved a relative standard deviation for 8 mass comparisons between 1,4∙10^-10 und 5∙10^-11. Commercial devices such as the two 1kg mass comparators CCL1007 (Sartorius) and M-one (Mettler) are designed as non-equal-arm beam balances with a parallel spring force input system according to the principle of electromagnetic force compensation (EMF) and achieve a relative standard deviation of 2∙10^-10 or 3∙10^-10 (200 or 300 nanograms).

The joint long-term goal of the research group is to penetrate the physical limits of precision weighing technology. Disturbing influences and effects are to be fundamentally investigated and modeled. Based on this, improvements are to be made in the field of construction, control technology and electronics. A relative standard deviation of the mass differences of 5∙10^-12 (5 nanograms) is aimed for comparisons of 1 kg mass standards. Currently 50 nanograms are reached here. The goal is therefore a reduction of the standard deviation by a factor of 10. There is a very high demand for both the practical transfer of the SI unit kilogram and for basic research after a possible redefinition.

TU Ilmenau - FG Compliant Systems

TU Ilmenau - FG Process Measurement

TU Ilmenau - FG Theoretical Electrical Engineering

TU Ilmenau - Institute for Micro- and Nanotechnologies IMN MacroNano®

01.01.2018 - 31.12.2021

This project is granted by the Carl-Zeiss-Stiftung