Rotating-coil calibration in a reference quadrupole, considering roll-angle misalignment and higher-order harmonics

Abstract

Measurement of magnetic fieldMagnetic field in electromagnetism a b s t r a c t A method is proposed for calibrating the radius of a rotating coil sensor by relaxing the metrological constraints on alignment and field errors of the reference quadrupole. A coil radius calibration considering a roll-angle misalignment of the measurement bench, the magnet, and the motor-drive unit is analyzed. Then, the error arising from higher-order harmonic field imperfections in the reference quadrupole is assessed. The method is validated by numerical field computation for both the higher-order harmonic errors and the roll-angle misalignment. Finally, an experimental proof-of-principle demonstration is carried out in a calibration magnet with sextupole harmonic.

Precision Analysis and Design of Rotating Coil Magnetic Measurements System

“…The signal, received by the coil when the rotation cuts through the magnetic field, looks like a harmonic wave with the same wavelength as the number of poles of the electromagnet and amplitude. The position of 0-360 degrees around the magnetic cavity depends on the torsional angle of the coil that crosses a magnetic field whose direction is perpendicular to the motion [19][20][21][22]. Lastly, (3), analyzing the impacts on the accuracy of the electromagnetic field measurement based on the error value of the controlled speed and the orbit movement of the shaft with the coil as well as signal analysis using fast Fourier transform [23][24][25] for indicating the feature of orbits used for measuring the magnetic fields of each axis.…”

Calibration technique for rotating PCB coil magnetic field sensors

“…where pick-up coils are implemented with multi-turn windings or Litz wire hand-wound on a grooved ceramic shaft [4] [5], several standard methods have been developed to achieve good calibration [4][5][6][7]. Some of these require the use of highaccuracy linear stages, calibration magnets and special tooling [6] [7]. In actual measurements, imperfections in motion of the probe [8] [9], e.g.…”