A three‐dimensional magnetic field mapping system for deflection yoke of cathode‐ray tube

Abstract In this paper, we introduce an efficient three‐dimensional magnetic field mapping system for a Deflection Yoke (DY) in Cathode‐Ray Tube (CRT). A three‐axis Hall probe mounted in a small cylindrical bar and three‐stepping motors placed in a non‐magnetic frame were utilized for the mapping. Prior to the mapping starts, the inner contour of DY was measured by a laser sensor to make a look‐up table for inner shape of DY. Three‐axis magnetic fields are then digitized by a three‐dimensional Hall probe. The results of the mapping can be transformed into various output formats such as multipole harmonics of magnetic fields. Field shape in one, two and three‐ dimensional spaces can also be displayed. In this paper, we present the features of this mapping device and some analysis results.