36
37
English
Quartz watches
Precision tolerances
3
The precision of a mechanical movement depends on the individual
habits of the wearer and can therefore vary. A qualified
OMEGA
watchmaker can adjust the precision of a watch to within the
OMEGA
tolerances, which are from -1 to +6 seconds per day.
Other
OMEGA
mechanical watches
Watches without chronometer certification (COSC) have average
precision tolerances of between -1 and +11 seconds per day.
The precision of a mechanical movement depends on the individual
habits of the wearer and can therefore vary. A qualified
OMEGA
watchmaker can adjust the precision of a watch to within the
OMEGA
tolerances.
Quartz watches
All
OMEGA
quartz movements are produced in accordance with
OMEGA
’s highly renowned procedures and quality standards. Ambient
temperature may affect the precision of quartz movements, which can
lead to variations of between -0.5 and +0.7 seconds per day.
Quartz watches with thermocompensation
(calibre 1680)
This movement is fitted with an electronic module that compensates
for the effects of temperature on the movement’s precision. These
watches are accurate to /- 0.055 seconds per day.
The precision of a mechanical watch cannot be compared to that of a
quartz watch, given that the two are based on different technologies.
U
Helium escape valve
Specifi c sections/general information
4
Your
OMEGA
Seamaster Professional Diver is the watch for pro-
fessional and amateur divers, as well as demanding sportsmen and
–women. A robust design, the new helium escape valve (exclusive
OMEGA
patent), together with all the protection systems, offer opti-
mal security and reliability. In order to ensure that your watch remains
watertight, we recommend that you have it checked by an authorised
OMEGA
partner every year.
Helium escape valve (fig. 1)
Why a helium escape valve? Air
cannot be used for deep-sea dives,
since oxygen (a constituent element
of air) becomes toxic at a depth of
60 metres. Therefore, when carrying
out work at great depths, profes-
sional divers stay in a diving bell for
several days, breathing a mixture
of gases containing a high proportion of helium. The pressure is
gradually increased to reach the pressure at the working depth. The
divers, still inside the bell, are then lowered to the working site. They
leave the bell to carry out their work.
Once their work is complete, they re-enter the bell, which is then
raised to the surface. Pressure is then returned to atmospheric levels
and this is when the valve must be opened (only for deep-sea dives
lasting several days).
The helium molecules diffuse and penetrate the material of the gas-
kets. The quantity is sufficient to push out the crystal during the return
to atmospheric pressure. To avoid this, the Seamaster Professional
Diver is equipped with a valve specially developed by
OMEGA
.
60
45
50
55
5
30
10
20
60
20
40
12
PROFESSIONAL
CHRONOMETER
300m/1000ft
8
fig. 1
q
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