HOSS - Owner's Manual 39
ELECTROMAGNETIC INTERFERENCE
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 to electromagnetic energy (EM) emitted from
sources such as radio stations, TV stations, amateur radio (HAM) transmitters, two-way 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, 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.
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 include: citizens band (CB) radios, "walkie talkie," sec-
urity, 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 while 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 vehicle; and
3)
Long-range transmitters and transceivers,
such as commercial broadcast transmitters (radio
and TV broadcast antenna towers) and amateur (HAM) radios.
NOTE:
Other types of hand-held devices, such as cordless phones, laptop computers, AM/FM radios, TV sets,
CD players, and cassette players, and small appliances, such as electric shavers and hair dryers, so far as we know,
are not likely to cause EMI problems to your powered wheelchair.
EFFECTIVE DECEMBER 2, 1994 THE FEDERAL GOVERNMENT REQUIRES THIS STATEMENT TO BE INCLUDED.
