cc.powell
14
Depends who you talk to
When I bought my JLC Master Control Calendar I asked the AD if it was COSC certified like my Rolex. He said it wasn't but JLC and "higher end" manufacturers don't need to get COSC certification to prove accuracy as their standard accuracy is better than the COSC guidelines. That seemed fair enough. However my JLC gains about 1 minute per week (about 8 seconds/day), which would not pass the COSC test. My 20 year old Rolex gains about 1 minute per month (about 2-3 seconds/day).
That being said I love my JLC and for ultimate timekeeping I have a Casio Waveceptor watch that I set my other watches to.
Colin
Accuracy of Ulysse Nardin’s non-COSC chronometer watches
Hi! I have a question about the accuracy of Ulysse Nardin’s non-COSC chronometer watches. As I travel quite a bit, I am considering purchasing either a UN GMT +/- Big Date or a UN Michelangelo UTC Dual Time. Before spending several $’000 on a watch, I was...
My experience
I believe UN’s official position is that variations of 6 – 12 sec/day are normal. However, my Sonata Silicium is not COSC certified. It ran a very consistent +3/sec per day when I first received it. I sent it to the US service center and they ...
I wouldnt worry about it too much
Cosc is overrated any good watch company makes there watches to even better than cosc standards and your UN will run fine too i have a BP which is not cosc and runs 3 sec a day i believe that a lot a watch companies use the Cosc tag to promote and market ...
Depends who you talk to
When I bought my JLC Master Control Calendar I asked the AD if it was COSC certified like my Rolex. He said it wasn't but JLC and "higher end" manufacturers don't need to get COSC certification to prove accuracy as their standard accuracy is better than t...
My Pam had the JLC too
and ran about 3 sec s a day and it wasnt cosc and was always accurate has your always run at 8 secs ? might need to be checked over