Omega Speedmaster Pro accuracy

[Seppo Martikainen]

Hi,

I just bought the Omega Speedmaster Professional. I'm a total
beginner in horology so I would like to ask a question about the
accuracy of the watch. How many seconds in 24 hours +- is
acceptable for this watch (or a mechanical watch of this kind in
general)? Mine is about 6 seconds fast per 24 hours. Also how
often should the watch be wound? Mine seems to run at least 48
hours with one wound.

I'm also interested in reading about related subjects so if you
know good WEB sites, etc. Please let me know.

Thanks,
Seppo

[Rob]

Seppo, your watch is doing great. 6seconds per 24 hours is quite good. It
can be adjusted further, but that will be quite difficult. The 48 hour
reserve is what every normal hand wound watch has.

Robert
--
+++++++++++++++++++++++++++++++++++++++++++++++++
+ Robert Keulen | R.Ke...@MP.TUDelft.nl +
+++++++++++++++++++++++++++++++++++++++++++++++++
http://home.mp.tudelft.nl/~mp431011/

[won...@ibm.net]

> Seppo Martikainen <10075...@CompuServe.COM> writes:
> Hi,
>
> I just bought the Omega Speedmaster Professional. I'm a total
> beginner in horology so I would like to ask a question about the
> accuracy of the watch. How many seconds in 24 hours +- is
> acceptable for this watch (or a mechanical watch of this kind in
> general)? Mine is about 6 seconds fast per 24 hours. Also how
> often should the watch be wound? Mine seems to run at least 48
> hours with one wound.
>
> I'm also interested in reading about related subjects so if you
> know good WEB sites, etc. Please let me know.
>
> Thanks,
> Seppo
>
>>>>

The following is excerpt from The Mechanical Adviser published by Swiss Prestige. It might be of interest to
you.

'Customers often complain about the accuracy of their mechanical watch. Assume your watch is gaining or
losing 12 seconds per day. This tolerance is normal and acceptable even for expensive watches, or
movements with "Chronometer Certificates". Relatively seen, this tolerance of 12 seconds is irrelevant. 12
seconds per day works the incredible tolerance of 99.985%! Even calculated for a whole month (30 days)
during which period your watch gains or loses 360 seconds (or 6 minutes), those little mechanical
wonder-pieces still command an accuracy of 99.983%. What more can you expect?

If you bought a car, whose top speed is promised to be 200 km/h, and it reaches only 199.166km/h, you
would not return it to the service centre and complain. Even the earth does not turn around in exactly 86,400
seconds. Why then do people expect such an incredible performance from a little mechanical timepiece?

Contrary to the beliefs of many, an automatic (or self-winding) movement is not more accurate than a
hand-winding one. This feature has absolutely no influence on the accuracy whatsoever.

What tolerance is acceptable?

We classify the movements in 3 categories:

Normal movements - the torelance should be below 20 seconds.
Chronometer movements - the tolerance should be below 15 seconds a day.
Tourbillon movements - the tolerance should be below 10 seconds a day.'

BTW, how can you be sure your Omega Professional is 6 seconds fast per day. How accurate is your base?

With regards,

Terence
won...@ibm.net

[Alan Downing]

Hi Seppo,
Your speedmaster has a Lemania Cal. 1873/4 shuttle chronograph
movement which can be adjusted to within chronometer norms.
Most good mechanical watches are adjusted to gain not more
than 10 seconds a day. Regular gain or loss means your watch
is accurate.Erratic performance means you have a problem.
The timekeeping performance of your watch will depend on
how often you wear it and your lifestyle.
Using the chronograph could have an effect on the amplitude
of the balance.But in general you can be perfectly satsified
with the performance of your watch.
You should wind your watch at the same time every day.
A power reserve of 498 hours is acceptable although twin-barreled
watches now boast 100 hours.After running for about 30 hours
diminishing power from the mainspring barrel will slow down your watch.
That's all

Regards,

Alan
dow...@iprolink.ch

[Richard Sexton]

In article <4mcq3o$2u...@news-s01.ny.us.ibm.net>, <won...@ibm.net> wrote:
>What tolerance is acceptable?
>
>We classify the movements in 3 categories:
>
>Normal movements - the torelance should be below 20 seconds.
>Chronometer movements - the tolerance should be below 15 seconds a day.
>Tourbillon movements - the tolerance should be below 10 seconds a day.'
>
>BTW, how can you be sure your Omega Professional is 6 seconds fast per day. How accurate is your base?
>

Well, I use a cesium clock slaved to the National Reseach
Council source in Ottawa.

In 1976 I bought myself a Rolex Datejust. It was gaining
5 seconds a day, and since it cost the princly sum of $400
I took it to Rolex on Richmond St. and complaind about it,

A nice man in a white lab coad, upon hearing my story
went "tsk tsk" and went away, only to return a few minutes
later and stated in a thick German accent: "now zee watch
iss perrrrfect" and indeed it was accurate to a second
a day.

In fact it was more accurate than a friends quartz LCD
watch at the time. His gained a two seconds a day, mine
lost one.

I lost the fucking thing in the Pacific Ocead while surfing
after eating a dubious catci (Trichocerus pachenii) during
the 1980 4th of July celebration at Dockweiller beach
at the end of the Los Angeles airport runway.

If you find a watch like this, with "RJS 76" engraved
on the back, it's mine.

You fly over it almost every time you fly in and out
of LA.

It's down there, *somewhere*.

--

Richard J. Sexton | VRx Network Services - WWW R&D
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