Charts for estimating the axial shielding factors of open-ended cylindrical shields

Axial shielding factors of single and double-shell open-ended cylindrical magnetic shields are calculated numerically and represented by charts. It is assumed that the thickness of the shells is small (1%) compared to the largest diameter and the permeability is independent of magnetic induction. Dependencies of the axial shielding factors on the shields´ geometry and permeability are calculated numerically and represented finally as logarithmic-scale contour plots. Single-shell shields are described by one chart only where the length-to-diameter ratio (1 to 10) and the permeability (10¹ to 10⁴) normalized to the thickness-to-diameter ratio are variable parameters. Double-shell shields are described by a set of charts where the ratio of the shells´ lengths (0 to 1) and the normalized permeability are variable parameters while the outer shell length to diameter ratio (3, 4, and 5) and the ratio of the shells´ diameters (0.5, 0.6...0.9) are fixed parameters