13
2. Additional timing:
This function enables several consecutive times to be measured by totalizing
to obtain the aggregate total time.
1.
Start time 1:
push-piece A (START)
2.
End time 1:
push-piece A (STOP)
>
Read time 1
3.
Start time 2:
push-piece A (START)
4.
End time 2:
push-piece A (STOP)
>
Read time 1 + time 2
etc.
5.
Zero reset:
push-piece B
A u t o m a t i c h e l i u m e s c a p e m e n t v a l v e
The automatic helium escapement valve
(fig. 7)
meets the needs of hyperbaric
divers who spend several days in diving
caissons and breathe a gas mixture which
is highly enriched with helium.
Helium is a very light and volatile gas,
which may infiltrate the chronograph on
exposure to substantial pressure in the
caisson. When the diver rises to the surface,
all the gases expand as the pressure falls.
The helium trapped in the chronograph is
unable to escape as quickly as it entered.
Overpressure builds up inside the case and
the valve will automatically be actuated to
allow the helium to escape, thus preventing
damage to the chronograph.
fig. 7
Automatic valve
