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Helium escape valve
Specific sections/general information
3
How to use the helium escape valve
Manual helium escape valve:
If your watch features a manual helium escape valve, the escape valve
must always be screwed-in when diving so as to ensure perfect secu-
rity against potential water entry.
The escape valve must only be unscrewed during the decompression
phase (when the diver is returned to atmospheric pressure levels)
inside a hyperbaric chamber.
NB:
Even though the escape valve is unscrewed, the watch remains
water resistant to a pressure of 5 bar (50 metres / 167 feet).
Nevertheless, it is recommended that you always swim or dive with
the escape valve screwed-in.
Variation with position indicator: the
escape valve is equipped with a red
indicator (A) that is visible in the uns-
crewed position.
Variation with corrector: the escape
valve is equipped with an integrated
date corrector. The corrector (B) posi-
tioned in the centre of the escape valve
is functional when the escape valve is
fully screwed-in.
Automatic helium escape valve:
if your watch possesses an automatic
helium escape valve (C), no manipula-
tion is necessary.
A
B
C
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
Specific sections/general information
3
