Small mass value realization equivalent to accuracy class E1 using the Planck-Balance at PTB

Abstract The Planck-Balance (PB) is a compact Kibble balance, designed for the realization of the unit of mass at values much smaller than 1 kg across multiple orders of magnitude. Recent advancements enable the PB at PTB to measure mass with uncertainties equivalent to calibration accuracy classes E1 (up to 5 g), E2 (up to 50 g), and F1 (up to 100 g), while operating in air. Type B uncertainties limit the relative combined standard uncertainty for a mass of 100 g to the minimum achievable value of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>4.5</mml:mn> <mml:mo>⋅</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>7</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> . A measurement campaign was conducted using six mass standards (1 mg, 10 mg, 100 mg, 1 g, 10 g, and 100 g), yielding results consistent with the values specified in their E1 calibration certificates. The presented results demonstrate the feasibility of metrologically traceable small mass measurements without reliance on mass standards. Unique design features of the PB will be discussed, including a rigidly mounted coil that minimizes geometrical alignment requirements, and an oscillatory velocity mode that achieves a high signal-to-noise ratio, even with a movement range of less than 0.2 mm. This approach could offer an alternative to calibration and dissemination using mass comparators.