Updates on the Tsinghua Tabletop Kibble Balance

TL;DR

This paper reports on the progress of the Tsinghua tabletop Kibble balance, a compact and precise instrument for mass measurement based on the SI redefinition, highlighting system development and key experimental achievements.

Contribution

It presents the development and characterization of a high-precision, user-friendly, and cost-effective tabletop Kibble balance system for mass realization.

Findings

Successful construction of the magnet system

Determination of absolute gravitational acceleration

Development of a high-precision current source

Abstract

With the adoption of the revised International System of Units (SI), the Kibble balance has become a pivotal instrument for mass calibrations against the Planck constant, $h$. One of the major focuses in the Kibble balance community is prioritizing experiments that achieve both high accuracy and compactness. The Tsinghua tabletop Kibble balance experiment seeks to develop a compact, high-precision, user-friendly, cost-effective, and open-hardware apparatus for mass realization, specifically within the kilogram range. This paper reports on the progress of the Tsinghua tabletop Kibble balance project over the past two years. Various aspects of the Tsinghua tabletop system, including electrical, magnetic, mechanical, and optical components, are summarized. Key achievements, such as the construction and characterization of the magnet system, determination of absolute gravitational acceleration, investigation of a capacitor-sensor-based weighing unit, and development of a high-precision current source, are presented to provide a comprehensive understanding of the experiment's status.