Beurer PM 62 Gebrauchsanleitung Seite 40

What kind of causes for interference are there?
In some situations, short-range electromagnetic interference can occur.
In order to avoid these, keep well away from these sources.

Nearby power lines

Walking through security gates in airports.

Nearby overhead lines (tram)

Nearby traffic lights, television sets, car motors, bike computers

Nearby exercise equipment

Nearby mobile phones
Interference from other devices for measuring heart rates
The HR monitor as a receiver can react to interfering stray signals such
as other heart rate monitors within a vicinity of one metre. This can
result in incorrect measurements particularly when training in groups. If
you e.g. jog next to one another, it can be beneficial to wear the HR
monitor on the other wrist or to increase the distance to one's training
partner.
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