zOwie Omega Discussion Forum

Regarding mechanical SeaMaster accuracy -

I recently purchased a new Seamaster at a jewelry
store in Annapolis Maryland, on 1-10-2001.
I ran a series of accurcy tests on 2-14-2001.
The test method used is as follows :

For each test, I recorded the sound of the watch ticks over an interval of about 66 seconds. I then measured the time duration of 480 ticks, or one minute. (8 major ticks per second)

I recorded the ticks using my computer's sound
card, in this case a Turtle Beach "Pinnacle" sound card.
Although the sampling rate is supposed to be
44,100 samples per second, I found that my card
actually samples, at about 44061.558 sps.
This was determined by recording clock ticks from
WWV, the radio station in Fort Collins, Colorado,
which broadcasts time signals from the official
"Atomic Clock", which I think averages the signals from seven atomic clocks running concurrently. Suffice it to say, their signals are extremely accurate.

I then measured the accuracy of in watch in several different positions, and at several
time intervals after being "fully" wound.
The temperature in all the tests was about
73 degees F +/- 2 degrees.

This method isn't perfect, but the results should be pretty good. So long as my sound card's master clock is consistent, its slight error is unimportant, it's just important to know what the sampling rate actually is.

To determine the time duration of the 480 ticks,
I used a program called Cool Edit 2000, which allows the user to directly read the sequential value of the sample in the recording.

Measurements were made. immediately after fully winding, about 8 hours after fully winding, about 13 hours afetr fully winding, and finally at 24 hours after fully winding, just prior to being wound again.

The watch positions checked were as follows:

These positions correspond to easily repeatable positions that my watch can be placed in, as a result of the particular sizing of my bracelet,
and in combination with placing pennies under the one of the folds in the bracelet.
The important thing is that in each case, the angle the face of the watch makes with the horizontal was measured. All of the measurement
positions are basically variations of "face-up", the only difference being the angle face makes with the horizontal. (That is, in each case, the
3 and 9 o'clock positions were always level, but the angle of the face from 6 to 12 o'clock varied.)

The positions were :

6 o'clock position higher than 12 o'clock pos,
with face forming 4 degree angle with horizontal.
I call this position "6-up04"

12 o'clock position higher than six o'clock position, withe face forming 25 degree angle with
horizontal. I call this position "12-up25".

Using this same position naming convention, the other positions were

12-up36
12-up38
12-up40
12-up42
12-up44
12-up45
and finally
12-up61. (where the angle formed with the horizontal is 61 degrees).

Finally the results !!! (fast or slow in seconds per 24 hours)

Position/just after winding/after 8 hrs/after 13 hour/after 24 hrs.

6-up04/7.36F/5.28F6.87F/7.76F

12-up25/5.04F/4.66F/5.53F/5.60F

12-up36/.93F/.11F/.44F/3.41S

12-up38/1.47F/.21F/.08F/3.69S

12-up40/.81F/.01S/.76F/2.93S

12-up42/1.00S/1.34S/1.05S/2.74S

12-up44/.91S/1.77S/.23S/5.18S

12-up45/.95S/3.39S/1.23S/6.37S

12-up61/8.44S/7.52S/8.97S/8.59S

When the watch is actually worn on my wrist, it runs a bit fast, I'd say it gains about 1/3 second per hour, on my wrist.

However, by using the above information, I never have to reset my watch. If it is a little "ahead"
the exact time, I'll just position the watch to slow down a bit, usually the "12-up61" position;
if the watch is "behind" the exact time, and I want it to "pick up" a second from 10 Pm till 8
Am the next morning. I'll set it in the 12-up25 position. If I want it to "pick-up" faster. I'll use the "6-up04" position.

I expect that these values will changes as the watch "breaks in".

If your watch needs a service adjustment, I'd suggest sending it to an Authorized Omega
service center, either at

The Swatch Group in Toronto, Ontario,
or the Swatch Group in the USA in Lancaster, Pennsylvania. Contact them first before sending it.

I feel confident that they can get your watch to run more accurately.

Good luck,

Chris Petroski
USA
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P
pennsylvaniasa
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