a matter of principle, keep your watch as far away from magnetic fields
as possible. Mechanical watch movements all contain parts that can be
magnetized, depending on the strength of the magnetic field.
the laws of physics: certain watch models, feature an inner case made
of soft iron as additional protection against magnetism.
to the DIN 8309 standard, a watch is classified as anti-magnetic if it
continues to function satisfactorily when exposed to a homogeneous
magnetic field with a strength of 4800 A/m, or approximately 60.3
oersted. In today's world we are continuously exposed to electromagnetic
fields of differing strengths. The strongest fields we encounter in the
course of our everyday lives are those generated by televisions,
computer screens, power lines and radio masts.
metal case of a wristwatch functions rather like a Faraday cage and
protects the movement against most magnetic fields. Nevertheless, a
watch movement can be magnetized unintentionally. If this happens, it
will inevitably be less accurate and the rate will be irregular. If this
does happen, your watchmaker has special equipment that will
demagnetize a mechanical watch quickly and simply.
the case of a quartz watch, the entire procedure is all a little more
difficult. Quartz watches have a stepping motor that contains a rotor
with a permanent magnet, whose strength is affected by external magnetic
fields and, in a worst case scenario, can even be destroyed. In short,
avoid exposing your wristwatch to strong magnetic fields over extended
periods of time.