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English
Helium escape valve
Specifi c sections/general information
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How to use the helium escape valve? (fig. 2)
In its normal position (fig. 2.1), the
OMEGA
helium escape valve is
perfectly watertight thanks to the gaskets (B), but it is not functional,
since it is screwed down.
During the decompression phase, unscrew the crown of the valve in
order to release the mechanism (fig. 2.2). The valve is now water-tight
from the outside. As the interior pressure becomes greater than the
exterior pressure, it pushes the gasket (A) out of its seating, thus relea-
sing the gas (fig. 2.3). Once the pressure is equalised, gasket (A) returns
to its original position, pushed by the spring (C) (fig. 2.2).
This operation is automatically repeated several times during the
decompression phase. Once atmospheric pressure is reached, screw
down the crown of the valve (fig. 2.1).
Note:
Even if the valve is unscrewed, and we strongly recommend
that the valve remains screwed down whenever the watch is immersed
in water, the watch is still water resistant to a relative pressure of
5 Bar (50 metres). However, complete water resistance to the dial
depth can only be achieved with gasket (B) and the valve in the
screwed down position.
Automatic helium escape valve:
if your watch is equipped with
an automatic helium escape valve, no manipulation is required.
B
A
C
fig. 2.2
fig. 2.3
fig. 2.1
fig. 2
q
The desired information (tachometer; pulsimeter) is read off between
the central seconds hand of the chronograph and the correspond-
ing scale, over a maximum duration of 60 seconds. For the telemeter,
it is possible to make use of the minutes counter by adding 20 km
to the distance indicated by the central seconds hand for each
minute elapsed.
Using the tachymetric scale
Example: calculating the speed of a car.
Record the time the car takes to cover
a distance of 1 kilometre. Read off the
tachymetric scale the speed indicated by
the central seconds hand. In this case,
the car is travelling at 120 km/h.
Using the pulsimetric scale
Example: calculating the number of
heart-beats per minute.
Start the chronograph, count the heart-
beats and stop it at the beat correspon-
ding to the scale graduations of your
chronograph (here to the 30
th
beat).
Read the number of beats per minute
off the pulsimetric scale: here, 60 beats/
minute.
Measurement scales
Specifi c sections/general information
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