Sigma onyx FIT Mode D'emploi page 70

Why does the display react slowly or is coloured black?
The operating temperature may be too high or low. Your heart
rate monitor is designed for temperatures between 0°C and
55 °C (32 - 140 degrees F).
What should I do if the screen display is weak?
A weak display may be due to weak batteries. You should
change them as quickly as possible
– battery type CR 2032 (Item No. 00342)
PAGE 32
7.3 Beep
The different volume settings are:
summary
Button tones:
Button tones give the user acoustic feedback
each time a button is pressed.
Zone alarm:
The zone alarm is an acoustic signal when the
user changes from one training zone to the next.
Training tones:
Training tones always sound when the watch switches
from one training phase (e.g. warm-up) to another
(e.g. workout).
1 x long:
k When entering Zone 1
k always when a recovery pulse is
saved (0 sec, 30 sec, 60 sec, ...)
2 x long:
k When entering Zone 2
k if there is only one zone, when
entering this zone
3 x long:
k When entering Zone 3