Hi all,

Thanks for the forum, quick question: I planned on buying one (I like the constellation) till I heard that magnetic fields do have an effect on the watch and its functioning. I am now again looking, and am confused:

Looking at one of the Omega pages, it seems to imply that all watches that have the 8500 and above are resistant to magnetic interferences, and another page states that it is only the Master Co-Axial? Did I misunderstand, and is there even a connection?

Can somebody please guide me: which one is it?

• Are all watches ok?
• Or any watch that displays a certain movement number and above?
• Only the Master Co-Axial models?

Thanks for any input that I can get.

Kind regards.

 

8500 + "master co-axial" on dial = a-magnetic movement

8500 without "master" = not a-magnetic movement

 

One exception: the Aqua Terra >15,000 Gauss "Bumblebee" has the anti-magnetic 8508 but does not say "master" anywhere.

Note that any of the 8500/9300/3330 etc. with the Si14 silicon balance spring will probably be more resistant to magnetic fields but not in the same range as the master co-axials.

 

Absolutely right.

 

Master is super-antimagnetic. Regular Si14 is antimagnetic enough.

 

I believe no watch can be anti-magnetic, as it doesn't do anything against magnetic fields. But it can be resistant to magnetic fields, so be amagnetic.

 

So... I have a Co-Axial not a "master".

Apologies if this is a noob question, but how is my watch less amagnetic?

I have the silicon balance wheel.

Thanks.

 

An 8500A movement with the traditional balance spring will be like any other watch and the spring can be magnetized. No special anti-magnetic qualities in the 8500A.

8500B movements that have the silicon balance spring won't have a magnetized balance spring, but other parts of the watch can still be magnetized.

8500G or the 8508 that are made to the new anti-magnetic standard have the silicon balance spring, and some other parts inside the watch are replaced by materials that are very resistant to being magnetized. Note that certainly not all parts inside these watches are made very resistant, just some. Many parts inside the 8500G can still be magnetized and are the same parts used in the 8500A.

Cheers, Al

 

Thanks Archer, I have been looking for this data online.

I appreciate the information.

 

I am interesting in the Seamaster Aqua Terra with either 38mm or 38.5mm case. It appears that there are two almost identical models (apart from the different date window positions and dial patterns) with different movements which are:

1). AQUA TERRA 150M - OMEGA CO-AXIAL MASTER CHRONOMETER 38 MM - 220.10.38.20.03.001 with OMEGA Master Chronometer calibre 8800
2). AQUA TERRA 150M - OMEGA MASTER CO-AXIAL 38.5 MM - 231.10.39.21.03.002 - OMEGA Master Co-Axial calibre 8500

My question is what are the differences in terms of the movement apart from the differences in the power reserve?

Please help, thanks!