Re: Why are consumer-grade quartz watches (deliberately set?) fast?

In article <lsthi5tdpbcdguorudccj8eerdcc5faudh@xxxxxxx>, Frank Adam <fajp@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Wed, 16 Dec 2009 07:03:04 -0800 (PST), NadCixelsyd
<nadcixelsyd@xxxxxxx> wrote:

Let me digress: When I was a child some 60 years ago, consumer-grade
watches were accurate to about twenty seconds per day. Then, Bulova
invented the Accutron with a tuning fork, which was accurate to two
seconds per day. Thirty (+/-) years ago, quartz watches typically had
an accuracy of better than one second per day.

If they're tuned as precisely as pollible, some quartz watches should
be a tad fast, some should be a tad slow. However, I've noticed that
every quartz watch that I've ever owned runs a bit fast. So I tried
an experiment with two inexpensive quartz watches. Measured weekly
(using eyeballs and www.time.gov) over a period of four months
(without resetting), one watch consistently gained 3.5 seconds per
week. The other watch gained 2.5 seconds per week. In other words,
if I could adjust these watches to slow down by 22 and 15 milliseconds
per hour, respectively, they would have been accurate to within one
half second at all times for the past four months.

Well, to answer simply, it is better to come up for air a bit early
than a bit late. :)
I know, it's only seocnds, but it is probably an ingrained thing in
the watch industry that a watch should always be set a bit fast.
The mechanicals we always set a couple of seconds fast as well.
Better quality quartz movements would probably be able to do much
better than they are so perhaps it could be set closer to zero, but
compensation is still black magic, so it makes sense to aim for a bit
over to cover worst case scenarios.

As a secondary question, are any consumer-grade quartz watches time-
adjustable? I realize that most consumers only need the time to
within a minute or two, but I'm finiky.

Can't think of one. Certainly not in the mainstream movements by ETA,
Ronda, Miyota and Seiko. Although Omega and Longines with ETA
movements did use a trimmable circuit specifically made for them, but
can't tell you if they still use those on current models.
I'll keep an eye out though.

If its fast at room temperature, I wonder if it changes strapped to the wrist.

If it were a really cool clock with a computer, you could manually reset programming to add or subtract
clock pulses so it would stay on time.

greg
.

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