Depending on the mfg date it could have the silicon balance springs and be relatively resistant to mag fields. If I recall correctly the early 8500's do not have that and can be affected by mag fields. Normally mag fields will affect a watch by causing timing errors not time reserve issues.
I am sure an expert can give more data. I did have a similar problem with my 2500 movement caused by a slight shock... I dropped it 2 inches onto a concrete counter.... my time reserve dropped to about 2 hours, fixed via an Omega Boutique under warranty...
Can you describe the reduction in time reserve? Is the watch keeping good time?
The above was in response to your original unedited first post.
My watch does have a silicon balance spring. I do mean the main springs, not the balance spring. What kind of material are the main springs of my 8500B watch made of? This must be very important to know because of the magnetism resistance of the watch and barrels with their twin springs.
I like to know what kind of material the main springs of the Omega 8500B in the barrels are made of? Are they magnetism resistant?
Kind regards,
Arno
I don't have the exact composition, but the majority of the mainsprings used by Omega/Swatch are made by Nivarox-Far, which is a Swatch group company. The mainsprings are typically some type of Nivaflex alloy grade, and I'm not sure anyone but the company knows the exact composition, but they are alloys generally made of 45% Cobalt + 21% Nickel + 18% Chromium + 5% Iron + 4% Tungsten + 4% Molybdenum + 1% Titanium.
Like most modern alloy mainsprings they are non-ferrous, so not generally affected by a magnet. I won't say all because someone will then come up with an example of one that is able to be affected by a magnet. I just tried using a magnet on some regular mainsprings for a generic ETA movement, and some for an 8500, and neither of them could be picked up with a magnet. I doubt your reduction in power reserve has anything to do with magnetism...
