Calibration Technique for Rotating PCB Coil Magnetic Field Sensors

TL;DR

This paper introduces a high-precision calibration method for PCB-based rotating coil magnetic sensors, improving measurement accuracy and enabling in-situ calibration during particle accelerator magnet testing.

Contribution

It presents a novel calibration technique that leverages precise PCB wire placement and dynamic in-situ adjustments to enhance sensor accuracy and reduce vibration effects.

Findings

Calibration accuracy validated with CMM measurements.

Method improves signal resolution and suppresses fundamental field.

Enables dynamic, in-situ calibration during measurements.

Abstract

A high-accuracy calibration of inductive coil sensors based on Printed Circuit Board (PCB), commonly used in rotating coil field measurements of particle accelerator magnets, is presented. The amplitude and phase of signals with and without main field suppression are compared in order to simultaneously determine both the PCB rotation radius and the transverse offset of its plane from rotation center. The accuracy of planar wire placement on the PCB boards is exploited to create loops highly precise in area which rotate at different radii. Such an area reproducibility and circuit geometry allow the suppression of the fundamental field, enabling the calibration, as well as improving signal resolution and mitigating vibration effects. Furthermore, the calibration can be performed dynamically, in-situ during measurements. Calibration accuracy is validated experimentally by referencing the PCB positions with a Coordinate Measuring Machine (CMM).