Omega Seamaster Aqua Terra 15,000 Gauss
Throughout history there have been many studies to eliminate or minimize these harmful effects of dire consequences for the stability of the motion of clocks, which have led to legendary pieces like the Ingenieur of IWC or Rolex Milgauss. Even the very Omega had already above its representative in this sector of timepieces, the Railmaster 1957.
The pursuit of the objective of dealing with magnetism in watches had, as one of its consequences, the publication of the international standard ISO 764 "Horology - Magnetic Resistant Watches" that defined, or defined, the resistance should be offered to mechanical movements magnetic fields.
Specifically, this standard indicates that the clock must maintain accuracy within a deviation of + / - 30 seconds / day as before the test to be recognized as resistant to magnetic fields.
The systems in place to achieve this resistance are basically two. The first consisting of using a soft iron box housed inside the main box and that clock in turn houses the mechanical gauge. This solution has two major drawbacks: firstly the thickness of the resulting assembly which generates timepiece having to integrate soft iron casing between the outer casing and the mechanical movement. Secondly, and as the inner box can not have openings that would alter the effectiveness of its purpose, the vast majority of timepieces equipped with this system could not be implemented in the dial one dater, or other digital display, to state precisely one window.
Obviously there is a third easy on your deduction limitation: the nonnegotiable soft iron box prevents the practice of providing attractive background seen the timepieces that allows enjoy the view of the mechanical movement it houses. Proof of these restrictions is that the renewed IWC Ingenieur collection presented during the month of January this year and in which renounced the reason for its legendary model after to show their movement through the sapphire crystal mounted funds in their boxes and digital displays can deploy both dater as, for example, perpetual calendar. Of all the new models, only the original reissue keeps Ingenieur Automatic magnetically shielded.
The second alternative responds to relatively recent studies and developments and all based on the search for new materials that are not affected by the influence of magnetic fields. Probably all these materials the best known is the silicon (SI14) as this has been the focus of study of various manufactures to manufacture certain components of the mechanical movement and, protagonist, the balance spring.