Permobil Chairman HD, Owner'S Manual

Page: 45 / 49

Owner’s Manual Chairman HD Important Information
Page 46
CAUTION! It is very important that you read this information
regarding the possible effects of electromagnetic interference
on your powered wheelchair.
Electromagnetic Interference (EMI) From Radio Wave
Sources
Powered wheelchairs and motorized scooters (in this text, both will be referred
to as powered wheelchairs) may be susceptible to electromagnetic interference
(EMI), which is interfering electromagnetic energy (EM) emitted from sources
such as radio stations, TV stations, amateur radio (HAM) transmitters, twoway
radios, and cellular phones.
The interference (from radio wave sources) can cause the powered wheelchair
to release its brakes, move by itself, or move in unintended directions. It can also
permanently damage the powered wheelchair’s control system. The intensity of
the interfering EM energy can be measured in volts per meter (V/m). Each
powered wheelchair can resist EMI up to a certain intensity. This is called its
”immunity level”. The higher the immunity level, the greater the protection.
At this time, requested immunity level as per EN 60601-1-2 is 3 V/m. The immu-
nity level of this powered wheelchair model as shipped, with no further modifi-
cation, is >20V/m in the range of 26 MHz to 950 MHz.
There are a number of sources of relatively intense electromagnetic fields in the
everyday environment. Some of these sources are obvious and easy to avoid.
Others are not apparent and exposure is unavoidable. However, we believe that
by following the warnings listed below, your risk to EMI will be minimized.
The sources of radiated EMI can be broadly classified into three types:
1.
Hand-held portable transceivers (transmitters-receivers) with the antenna
mounted directly on the transmitting unit. Examples includes: citizens band (CB)
radios, ”walkie talkie”, security, fire, and police transceivers, cellular telephones,
and other personal communication devices.
NOTE! Some cellular telephones and similar devices transmit signals while they
are ON, even when not being used.
2.
Medium-range mobile transceivers, such as those used in police cars, fire
trucks, ambulances, and taxis. These usually have the antenna mounted on the
outside of the wehicle.