Breitling and time changes

[jcs11236]

I purchased a used breitling chrono superocean A13340 a month ago. watch is in great condition. was originally purchased in 2009. Since i got watch it has been losing 10 sec a day which i know is off spec. but this past week it has started to lose 7 sec a day instead of its usual 10 sec. What makes the watch lose less time/speed up? watch has been kept on winder since i purchased it. i have wore it 3 times. will it keep losing less time/speeding up? is something off on watch?
any info will be appreciated.
Thank you

[CaptRimmer]

Hi jcs11236, congrats on the new purchase. Really nice watch.
When was the watch last serviced? If it hasn't ever had a service, three years is just about the start of the service window. Book it in to Breitling and they'll sort out the timing issue too.
What has caused the watch to lose 7 iso 10 seconds a day? Anyone's guess. Could be any number of things.
Any pictures of your lovely watch?
Cheers,
Capt

[Capt Spaulding]

I'm interested in the 'winder' you wrote about, I take it you mean a watch winder.

If it's powered by local a/c, have you had any outages or brownouts in the middle of the night, sometimes they happen without notice.

What brand is it btw? thx.

Cheers Spaulding.

[SnapIT]

Hello,

The Two Captains have some good points. I'll add that keeping a watch on a winder does not make for good time keeping. A watch is made to be worn thus subject to all of the variables that that brings with a modern life. A watch movement is designed to "average" the physical influences that wearing it have on the time keeping.

On a winder a watch is sort of in a soft sand box, not subject to irregular forces that would alter its performance across a day/night of activity. If a movement has a bias then it is exaggerated day to day as it spins quietly on the winder doing nothing much else then spinning. Set at a relatively constant temperature, pressure, vibration, acceleration and deceleration the movement happily chugs along doing what it does best, add up the passing seconds as it sees them go by.
Nothing disturbs this activity until the owner comes along and takes a reading, compares it against a time source and notices that his watch is loosing/gaining time after several days of passive accumulation of the time keeping bias of the movement.
Note this.. 4Hz x 2 x 60sec x 60min x 24hr = 691,200 oscillation of the balance wheel/pallet fork per day. It only takes a very small deviation to accumulate 10 seconds a day in either direction. If we are talking about CSOC spec then that is noted as -4/+6 under normal wearing conditions which as I have discussed is not the case for a watch on a winder. Taken another way ... 6/86,400 sec/day = 0.00694% drift. Change one factor like temperature and you could see an observable variation on a movements normal variation over a couple of days. Is the movement in need of repair, in my opinion, no. Is the owners understanding of time keeping conventions lacking, probably. Can this be corrected, easily! :- )

[jcs11236]

thanks for the replies everyone. I believe SnapIT is correct. i actually wore the watch this whole weekend. and now the watch is losing only 5 sec a day. actual physical movement is different from sitting on winder. wish i could wear watch more but my field of work doesnt allow me to. Weekends is only time to wear
Thanks again
here is a pic of my watch: