POLAR S720i - Manual (Page 94)

H 92
Electromagnetic interference
Disturbances may occur near high voltage power lines, traffic lights,
overhead lines of electric railways, electric bus lines or trams, televisions,
car motors, bike computers, some motor driven exercise equipment, cellular
phones or when you walk through electric security gates.
Exercise equipment
Several pieces of exercise equipment with electronic or electrical
components such as LED displays, motors and electrical brakes may cause
interfering stray signals. To try to tackle these problems, relocate the Polar
wrist receiver as follows:
1. Remove the transmitter from your chest and use the exercise equipment
as you would normally.
2. Move the wrist receiver around until you find an area in which it
displays no stray reading or flashing of the heart symbol. Interference is
often worst right in front of the display panel of the equipment, while
the left or right side of the display is relatively free of disturbance.
3. Put the transmitter back on the chest and keep the wrist receiver in this
interference-free area as far as it is possible.
4. If the Polar heart rate monitor still does not work with the exercise
equipment, this piece of equipment may be electrically too noisy for
wireless heart rate measurement.
Polar heart rate monitor and interference