3-D CROSSED YOKE TYPE FOR 2-D VECTOR MAGNETIC MEASUREMENT

摘要

Two-dimensional (2-D) magnetic measurement system has superior features to the conventional system such as Epstein tester and single-sheet tester. However, the conventional 2-D flat yoke type used in 2-D magnetic measurement system shows a measurement error due to the mutual interference by two different flows of magnetic flux. In this paper, we propose a three-dimensional (3-D) crossed yoke type for 2-D vector magnetic measurement in order to prevent the measurement error due to this magnetic mutual interference. By the result of 3-D static magnetic field analysis, we found out that 3-D crossed yoke type is superior to the conventional 2-D flat yoke type. The former can provide higher magnetic flux density and higher magnetic field strength than the latter, with better uniformity of the field quantities which makes the measurement more precise. We also got the result that the 3-D type has less influence of interference magnetic flux than the 2-D type, which is caused by an asymmetry of gaps between yoke and specimen.