23rd IMEKO TC 4 International Symposium and the 5th Chinese Conference on Electromagnetic Metrology Technical (IMEKO TC4 2019)

172 / 2019-03-17 21:21:52

Excitation frequency dependent deviations during the "velocity mode" of Bl measurements in the Planck-Balance

Planck-Balance,ac voltage,electromagnetic parameters,frequency measurement

Plenary track > System Identification and Control

The Planck-Balance is a table-top device that utilizes the concept of a Kibble balance. In contrast to a standard electromagnetic force compensated balance, the force factor Bl is not determined by calibration with mass pieces. Instead of this static calibration, the Planck-Balance applies a sinusoidal motion on the coil and determines the Bl based on measurements of induced voltage, displacement and frequency. In order to obtain valid force calibration for the weighing experiment, one has to ensure that the determined factor does not depend on the excitation frequency of the coil. A linearization of the control loop is established in order to reduce the harmonic distortion of the measurement signals. This work presents a method for reducing the frequency dependency caused by mechanical tilt oscillations and proposes a set-up to reduce the standard deviation of the determination of the Bl.