DavidBoettcher
Nuclear
- Nov 21, 2008
- 5
Wristwatches sometimes used to have the movement encapsulated in a soft iron housing to prevent the movement, particularly the steel balance spring, becoming magnetised. In the case of the IWC Mark 11 used by the RAF after WW2 this took the form of an iron ring around the movement with an iron back plate and iron dial plate so that the movement was completely enclosed in soft iron.
The use of soft iron, a ferromagnetic material, was intended to capture any magnetic field that the watch might encounter, keeping the lines of magnetic flux in the iron and channelling them around and away from the movement.
This encapsulation is often described as a Faraday cage. Is that the correct name for it, i.e. is it a special case of a Faraday cage made of ferromagnetic material?
Thanks for any help!
Regards - David
The use of soft iron, a ferromagnetic material, was intended to capture any magnetic field that the watch might encounter, keeping the lines of magnetic flux in the iron and channelling them around and away from the movement.
This encapsulation is often described as a Faraday cage. Is that the correct name for it, i.e. is it a special case of a Faraday cage made of ferromagnetic material?
Thanks for any help!
Regards - David