Extremely difficult to tell...

...and the maths doesn't really help in real world circumstances due to all the variables affecting both the watch and the surroundings - their resistivity, the temperature, etc.

The other thing to consider is that I don't have access to the actual test procedure used to determine the anti-magnetic number. Without this, it is difficult to determine how it might relate to real world use. (Not dissimilar to 'dive' watches that do not meet the ISO spec, yet proclaim huge depth numbers....without knowing the test procedure, who knows how long (and how) they resisted that pressure, how many were tested, etc)

So best bet is to find yourself a magnetometer and wander around near speakers, computers etc. That'll give you the best indication of what's out there.

This message has been edited by BDLJ on 2009-10-14 16:03:20

1000 Gauss watches: what can they stand?

By: Vlk : October 12th, 2009-13:32

Hi all, we all know some watches have the movement surrounded by a ring of soft iron to protect it from the influence of magnetic fields, up to usually 1000 Gauss or 80.000 Ampere/metre. Unluckily I was no good at physics, so I wonder what can generate su...

Gauss strength...

By: BDLJ : October 12th, 2009-19:15

Well, the difficult thing here is that Gauss and Ampere/metre aren't measuring exactly the same thing. Ampere/metre is a measure of the strength of a magnetic field (the B field), while Gauss (or Tesla) measures the flux density (the H field) In any case,...

Then, how useful is the 1000 Gauss protection?

By: Vlk : October 12th, 2009-23:30

Thank you for your answer, really useful. So if I put my antimagnetic watch really close to a great loundspeaker, it will soon stop working or, if I'm simply close at a certain distance I risk that my watch doesn't work properly. Said that, can we say tha...

You raise an interesting counter question...

By: BDLJ : October 13th, 2009-03:39

I do think they're useful. Imagine a watch with an old-syle blued hairspring. You'd have to be careful around fridge magnets! So the greatly increased non-magnetic qualities are definitely an advantage. But there are limits. In all these specifications or...

Good to know

By: Vlk : October 13th, 2009-04:29

I understand your point of view. I just thought it was hard to "beat" an antimagnetic protection up to 1000 Gauss while it seems we just need a good subwoofer to get a magnetic field that is 20 times stronger than 1000 gauss Of course, I'm not telling tha...

Current IWCs..

By: SteveW : October 14th, 2009-08:25

.. when they have enhanced magnetism at all are restricted to 80,000 A/m. Many of the formerly 'highly antimagnetic' Ingenieurs, for example, have succumbed to the display back disease - losing most of their resistance. There was a time, however, when IWC...

Extremely difficult to tell...

By: BDLJ : October 14th, 2009-16:02

...and the maths doesn't really help in real world circumstances due to all the variables affecting both the watch and the surroundings - their resistivity, the temperature, etc. The other thing to consider is that I don't have access to the actual test p...

An MRI is a mean machine ....

By: Marcus Hanke : October 15th, 2009-05:08

... for anything that is sensitive to magnetic fields. My wife works with a 3 Tesla MRI, her colleague already has grilled three (quartz) watches, because he forogt to take them off before entering the shielded room. Once, my wife had to rush in because t...

Wow...

By: Vlk : October 15th, 2009-11:55

...I couldn't imagine that magnetic fields had such a power. Thank you for sharing your experience. At the end, the only thing I can say is that the only anti-magnetic watch possibile is the one whose parts are not influenced by magnetic fields, which is ...

Hi Vic,

By: justpen : October 13th, 2009-05:53

Hi Vic, Just to confuse you further... or add to the discussion, Wikipedia have a pretty extensive say on magnetic watch resistance.... copy below. I have also had an interest in this subject, although my interest has been trying to decipher if the "soft ...