SEREN
ELECTROMAGNETIC INTERFERENCE
AND WARNINGS
3
CAUTION: It is very important that you read this information regarding the possible
effects of Electromagnetic Interference on your power chair.
Powered wheelchairs and motorized scooters may be susceptible to electromagnetic
interference (EMI), which is interfering electromagnetic energy (EM) emitted from sources
such a radio stations, TV stations, amateur radio (HAM) transmitters, two-way radios, and
cellular phones. The interference (from radio wave sources) can cause the motorized
scooter to release its brakes, move by itself, or move in unintended directions. It can also
permanently damage the motorized scooter control system. The intensity of the interfering
EM energy can be measured in volts per meter (V/m). Each motorized scooter can resist
EMI up to a certain intensity. This is called its "immunity level." The higher the immunity
level, the greater the protection will be. At this time, current technology is capable of
achieving at least a 20 V/m immunity level, which would provide useful protection from
the more common sources of radiated EMI. The immunity level of this motorized scooter
model is 20 V/m.
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.
Some cellular telephones and similar devices transmit signals while
they are ON, even when not being used.
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 include: citizens band (CB) radios, "walkie
talkie," security, fire, and police transceivers, cellular telephones, and other personal
communication devices.
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 vehicle.
Instruction Booklet
