Audemars Piguet Royal Oak Concept GMT Tourbillon Instructions For Use Manual - page 10
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2. A
bout t
he w
atc
h
Eng
lish
Functions
The Audemars Piguet Calibre 2913 qualif ies as an
extraordinary exploit. This manual winding movement,
with double barrel providing an exceptional ten-day
power reserve, combines a tourbillon and second time
zone display.
The tourbillon
The most out standing
watchmakers have been
s t r i v ing t o impro v e
t iming accurac y since
the second half of the
18
th
century. The desire
to achieve an identical
setting for a timepiece
in all positions is a major
challenge. Under the
Earth’s pull, the tiniest
variations in equilibrium have a negative influence
on the regulating part (balance/balance-spring) when
positioned vertically, thus causing running differences
in the watch.
In 1801 the watchmaker Abraham Louis Breguet
thought up a tourbillon regulating system that
balanced the running differences in all positions.
The operating principle has remained largely the same
to this day : the escapement parts (wheel, pallet
and balance) are held in a movable frame rather than
being fixed in the movement. By rotating on its axis
every minute with the escapement parts, this frame
enables all the parts to change position constantly,
thereby offsetting the running differences caused by
the effects of gravitation.
185 years later, in 1986, Audemars Piguet successfully
fitted this system for the first time into a production
wristwatch with an ultra-thin automatic mechanical
movement. The Manufacture in Le Brassus has since
built on this success by presenting many tourbillon
models combined with all watch complications.
The Manufacture, still one of the select few mastering
the secrets of this complication, offers more than
25 different tourbillon movements.
GMT display
Audemars Piguet launched its first wristwatch on
the market in 1990. This was the Dual-Time calibre
(2329/2846), with instant reading of the time in a
second time zone.
This particularly useful and appreciated
function is once more a feature in the Royal
Oak Concept GMT Tourbillon. The indication
of the second time zone, based on twelve
hours, comprises two discs making it easy
to tell the time. The first, on which the figures
are inscribed, completes one turn in twelve
hours. The second, just below, completes a
turn in 24 hours and has two coloured areas :
a white half for daytime and a black half
for night-time. This makes it easier to read
the figures.