Section 3-Emi Information - Invacare Leo Owner's Operator And Maintenance Manual

SECTION 3—EMI INFORMATION
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, 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",
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 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 pow-
ered wheelchair.
Part No. 1163141
WARNING
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SECTION 3—EMI INFORMATION
Leo Scooter