ENGLISH 27
8. PRECAUTIONS
8.1 Interference During Exercise
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 tackle
these problems, relocate the wrist unit as follows:
1. Remove the transmitter from your student’s chest and
continue using the exercise equipment normally.
2. Relocate the wrist unit you find an area in which it displays
no stray reading or does not flash 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 your student’s chest and keep
the wrist unit in this interference-free area as long as
possible.
4. If the heart rate monitor still does not work around the
exercise equipment, the piece of equipment may be
electrically too noisy for wireless heart rate measurement.
Crosstalk
When in non-coded mode
the wrist unit picks up transmitter
signals within 3 feet/1 meter. Simultaneous non-coded signals
from more than one transmitter may cause an incorrect readout.
Using The Polar Heart Rate Monitor in a Water Environment
Polar E40 heart rate monitor is water resistant and can be
worn when swimming. The heart rate monitor is not, however,
a diving instrument. To maintain water resistance, the buttons
must not be pressed under water.
Interference in a water environment may be due to the
following:
• Pool water with high chlorine content and seawater are very
conductive. The transmitter electrodes may short-circuit,
preventing ECG signals from being detected by the
transmitter.
• Jumping into water or strenuous muscle movement during
competitive swimming may cause the transmitter to shift to
a location on the body where it is not possible to pick up
ECG signals.
• The ECG signal strength is individual, and may vary
depending on an individual’s tissue composition. The
percentage of people who have problems in heart rate
measuring is considerably higher in water than in other
environments.
