Whilst mu metal is available in many different gauges and indeed a single layer of mu metal is suitable for most commercial applications, optimal shielding results are obtained when a shield is constructed of multiple layers of mu metal.

In theory each layer should be of a light gauge and the shield constructed of many layers (T. Rikitake – Magnetic and Electromagnetic Shielding 1987) in practice this not always possible from a mechanical point of view and it will be necessary to reach a compromise between number of layers for best shielding factor and structural requirements.

Evidence has shown that a multi layer shield of 4 layers has greatly improved shielding characteristics than one single layer of the same internal and external radii (example: 1 x layer of 10mm as opposed to 4 x layers of 1mm with 3 x 2mm air-gap) Adopting this method not only increases the shielding factor, it also Continue reading this post »