Invacare TDX Series Owner's Manual page 24

SECTION 1
CAUTION: IT IS VERY IMPORTANT THAT YOU READ THIS INFOR-
MATION REGARDING THE POSSIBLE EFFECTS OF ELECTROMAG-
NETIC 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 electromag-
netic interference (EMI), which is interfering 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 pro-
vide useful protection from the more common sources of radiated EMI.
This powered wheelchair model as shipped and MK5 electronics has a 20
volts per meter immunity level.
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," security, fire and police
transceivers, cellular telephones, and other personal communication
devices. **NOTE: Some cellular telephones and similar devices trans-
mit 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 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, 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.
TDX WHEELCHAIRS
All manuals and user guides at all-guides.com
WARNING
24
GENERAL GUIDELINES
Part No. 1114809