Planet Ocean 2500d accuracy seems to change sporadically

POinNY · Nov 12, 2017

Hi all-

I have a PO2500d that usually gains 3 seconds per day. This watch was serviced by the Omega Service center earlier this year as well. I’m a bit OCD about accuracy and I noticed something that may or may not be normal within a 24hour period. When I first set the time I make sure that the minute hand is set to the next minute and I bring the second hand right in the middle of the 12 marker and I use time.gov as a reference. As soon as the next minute starts I push the crown in. Here’s where things get interesting.

For example, on time.gov as soon as the 0:18 second mark hits, the second hand will be right on top of the 0:18 sec marker on my watch. Perfect, this is as it should be. Sometimes what happens is the very next minute when the 0:18 sec marker hits on time.gov, on my watch it’ll be on the 0:17 sec marker, so a second slow. If I check the very following minute it’ll usually resolve itself and both sources will sync up and be on the 0:18 sec marker at the same exact time.

Is this kind of fluctuation normal? I know I’m probably overdoing it by checking so often but now I’m not able to unsee this occurrence. How can the watch lose a second one minute and the very next minute it’ll fix itself?

Just want to know how normal this is. It happens maybe once every 24 hours, but possibly more if I paid more attention. The overall rate per 24 hours is +3 seconds but it’s the tiny fluctuations that happen in back to back minutes that has me curious.

Appreciate any insight.

keepitsimple · Nov 13, 2017

POinNY
Hi all-

I have a PO2500d that usually gains 3 seconds per day. This watch was serviced by the Omega Service center earlier this year as well. I’m a bit OCD about accuracy and I noticed something that may or may not be normal within a 24hour period. When I first set the time I make sure that the minute hand is set to the next minute and I bring the second hand right in the middle of the 12 marker and I use time.gov as a reference. As soon as the next minute starts I push the crown in. Here’s where things get interesting.

For example, on time.gov as soon as the 0:18 second mark hits, the second hand will be right on top of the 0:18 sec marker on my watch. Perfect, this is as it should be. Sometimes what happens is the very next minute when the 0:18 sec marker hits on time.gov, on my watch it’ll be on the 0:17 sec marker, so a second slow. If I check the very following minute it’ll usually resolve itself and both sources will sync up and be on the 0:18 sec marker at the same exact time.

Is this kind of fluctuation normal? I know I’m probably overdoing it by checking so often but now I’m not able to unsee this occurrence. How can the watch lose a second one minute and the very next minute it’ll fix itself?

Just want to know how normal this is. It happens maybe once every 24 hours, but possibly more if I paid more attention. The overall rate per 24 hours is +3 seconds but it’s the tiny fluctuations that happen in back to back minutes that has me curious.

Appreciate any insight.

Probably the best thing to do is to get the watch on a timing machine where the short term second by second performance can be checked. It's perfectly possible for a watch to appear to keep excellent time over days, but not perform well when analysed closely. However, this shouldn't be the case after a competent service of course, and a variance of a second a minute would be a massive and very unlikely issue with the movement
I think that time.gov adjusts itself for latency in some way. I don't know how well it does that, how valid that check is or how often the time is refreshed on the screen and latency updated. Also, I think there is more than one way to view the time on there. It may be that the display of the time reference against which you are checking has some slight issues.

POinNY · Nov 13, 2017

K keepitsimple
Probably the best thing to do is to get the watch on a timing machine where the short term second by second performance can be checked. It's perfectly possible for a watch to appear to keep excellent time over days, but not perform well when analysed closely. However, this shouldn't be the case after a competent service of course, and a variance of a second a minute would be a massive and very unlikely issue with the movement
I think that time.gov adjusts itself for latency in some way. I don't know how well it does that, how valid that check is or how often the time is refreshed on the screen and latency updated. Also, I think there is more than one way to view the time on there. It may be that the display of the time reference against which you are checking has some slight issues.

Thanks for the feedback. It is strange indeed. I know time.gov is the number 1 source that people just to measure accuracy against so I’d be surprised if there was an issue like that. Will a timing machine be a sure way to check for any issues?

keepitsimple · Nov 13, 2017

POinNY
.... Will a timing machine be a sure way to check for any issues?

Yes. Any watchmaker will be able to check it out (if they are prepared to). You might find your local Omega authorised dealer would do it too. If you're that OCD a cheap timegrapher is a useful tool at least to know if a watch is running well, but it may increase your OCD-ness 😒

I also use time.gov, but I'm aware that there may be potential issues surrounding the way latency is taken into account. It seems it is calculated and corrected for the path delay of the timestamp when you first log in, but not sure what happens after that. I always refresh the link immediately before checking the time. Also, if you have both the flash player version and the standard version running side by side, you may see they are very slightly different ;o) The loading on your computer may also affect the display. Your computer clock won't be uber-accurate, but you might try having that displayed too as a second reference. Also, GPS is very accurate if you have it.

Now if I could only figure out why my car's clock hasn't re-synced itself after we came out of daylight saving 2 weeks ago.....

Canuck · Nov 14, 2017

A timing machine “listens” to you watch for the few minutes it takes to bring the rate up to your satisfaction. To do this, the machine tells what the current rate would be over 24 hours- unless the rate changes as the watch runs for the 24 hours. That is the problem. Based on your level of activity, winding patterns, positional error, etc., the rate will vary from what the timing machine indicated. OCD people should buy quartz watches, IMO.

Planet Ocean 2500d accuracy seems to change sporadically

POinNY

keepitsimple

POinNY

keepitsimple

Canuck

Similar threads

Should I service my 2201.50 Planet Ocean (2500D)?

Really sporadic time keeping accuracy with PO8500

Omega Planet Ocean 2500D 2200.50 Black / Silver 45.5mm

Omega Planet Ocean 2500D 2209.50 Orange 42mm

Sudden recent timekeeping change on Ti Planet Ocean 9300 - why?

Sporadic time keeping with Planet Ocean 8500