Computational and Experimental Study of a Novel Open-Ring Measurement System for Weak Soft Magnetic Materials

This study presents a computational and experimental verification of a measurement system using slotted ring specimens for electromagnetically characterizing uncompressed, i.e., weakly magnetic, powders, which are promising materials for modern electric drives. Metrological challenges in characterizing weak magnetic bulk materials, such as the stray flux compensation, are addressed. Therefore, a new signal model is analytically derived and validated using 3D finite element analysis, ensuring an accurate indirect determination of the specimen’s averaged field quantities. A Monte Carlo analysis validates the sensitivity of geometric parameters and the achievable estimation accuracy compared to conventional setups using a closed ring-shaped specimen. Additionally, the novel setup and the introduced signal model are verified using 12 samples made of different iron powders.