Alpina AL-240, Гарантия и инструкции, Страница: 30 / 244

other functions 28
An essential feature of all Alpina diving
watches is the unidirectional, anti-clo-
ckwise, rotating bezel, used to control
immersion time. The bezel is fi tted with
a graduated scale divided into minutes.
The bezel’s working principle is both
simple and reliable. At the beginning of
each immersion, the zero on the bezel
must be aligned with the minute hand. A
simple glance at the position of the mi-
nute hand with respect to the bezel will
show the diver at any moment how much
time has elapsed since the start of the
dive (in minutes).
The unidirectional anti-clockwise rotation
of the bezel is a safety feature that en-
sures that any accidental movement of
the ring will always cause the remaining
diving time to reduce with respect to the
effective remaining diving time.
Measurement scales are scales that es-
tablish a relation between elapsed time
and another variable. The desired infor-
mation in terms of speed (tachymeter),
distance (telemeter) or units (pulso-
meter, productivity meters) is read off
between the central seconds hand of
the chronograph and the corresponding
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.
TACHYMETER SCALE USE
Example 1: calculating the speed of a car.
Measure the time it takes the car to cover a
distance of 1 km. Read off the speed indi-
cated by the central chronograph seconds
hand on the tachymetric scale. In our exa-
mple, the car is travelling at 90 km/h.
3.1
ROTATING
DIVING
BEZEL
3.2
MEASURE-
MENT
SCALES
AL Booklet Warranty-général-2015.indd 28 22/12/2014 11:01