Novel H-coil design with improved immunity to off-axis H components

Article type: Research Article

Authors: Zurek, Stan^b; | Rygał, Roman^a

Affiliations: [a] Magneto Sp. z o.o., Częstochowa, Poland | [b] Megger Instruments Ltd, United Kingdom

Correspondence: [*] Corresponding author: Stan Zurek, Megger Instruments Ltd, Dover, United Kingdom. E-mail: [email protected]

Abstract: Magnetic field strength H is often measured with so-called H-coils. These are typically wound with a wire on flat thin paramagnetic formers, which allows them to be placed as close as possible to the surface of the magnetic sample under test. However, such wire-wound H-coils are not completely immune to off-axis H components. This paper presents a novel concept of an H-coil design which significantly improves the immunity to off-axis components. Such H-coils can be made by utilising the precision of printed-circuit boards (PCB) and experimental results are shown for a prototype. PCB technology opens the possibility of making precisely aligned large H-coils, easy extrapolation of values towards the surface of the sample and accommodating wires for B-coils.

Keywords: H-coil, magnetic field strength, measurement uncertainty, rotational power loss

DOI: 10.3233/JAE-199329

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 61, no. S1, pp. S49-S56, 2019