Amongst the chronic weaknesses of the mechanical watch, acute sensitivity to magnetic fields is one of the greatest challenges for watchmakers. A mechanical watch exposed to the magnetic fields present in everyday life can not only lose its immediate precision, but its long-term accuracy may also be affected (causing a deviation of up to several minutes per day). The use of ferrous metals, particularly steel, in the production of calibers and their components is the cause of these malfunctions.
The range of exposure is wide, from the earth’s magnetic field of 0.5 gauss at our latitudes to MRI rays of between 15,000 and 30,000 gauss. However, magnetism is by no means a new problem for watchmakers. In days of old, the naval chronometers on board ships would react adversely when placed close to the deck compasses, so sailors had to ensure they were kept as far away as possible from each other. But the advent of a number of electrical devices has placed this particular weakness of mechanical watches under the spotlight once again.
From the digital alarm clock to the microwave and induction hob, many objects induce a magnetic flow. But as was demonstrated at the most recent Congrès International de Chronométrie, the most significant threats to mechanical watches come from radios, televisions, computers, and cell phones. Not to mention handbags—those with magnetic fastenings—which are positively toxic for watches. Current standards require timepieces to be able to withstand magnetic fields of at least 60 gauss. However, a watch placed near a cell phone is subjected to up to 750 gauss. In an ideal world, we should avoid bringing a mechanical watch into close proximity with any of these objects. The problem is so real that Omega estimates that 15% of after-sales maintenance operations are related to the demagnetization of watches.
To counter the adverse effects of magnetic fields, watchmakers developed materials that are less sensitive to magnetism, such as Invar, Elinvar, Nivarox and Glucydur—particularly for balance wheels and springs—and a few brands chose to protect their mechanical movements by means of a “magnetic shield”, often in the form of a soft iron cage. These solutions succeeded in reducing the effects of magnetism, offering resistance of between 1000 and 6000 gauss, but not in eradicating them completely, since the shield must necessarily incorporate openings to enable the hands or winding stem to pass through.
Omega has adopted a different tactic in order to resolve, perhaps permanently, the problem of magnetism. Nine patents later, the brand has unveiled a caliber which can withstand magnetic fields of over 15,000 gauss. To achieve this, the flagship brand of the Swatch Group decided not to protect the movement from magnetic fields, but rather to make it impervious to them. This was accomplished by employing only non-ferromagnetic materials. In addition to silicon, used since 2008 for certain springs, the axels and pivots are made out of Nivagauss™, the steel plates of the Co-axial escapement have been replaced by non-magnetic plates, and the spring of the shock absorber is made from an amorphous material.
After unveiling this technological breakthrough last year and proving its ability to find concrete solutions to watchmaking’s perennial problems, at Baselworld this year Omega made clear its intention to capitalize on these new developments—and to make them its hallmark. Four new “Master Co-Axial” calibers, capable of withstanding magnetic fields greater than 15,000 gauss, have featured on several new models. And the roll-out this magnetic resistance to all Omega movements must certainly be on its way.