Electromagnetic Interference And Warnings - Invacare Cetus Instruction Booklet

Cetus

ELECTROMAGNETIC INTERFERENCE AND WARNINGS

It is very important that you read this information regarding the possible effects of electromagnetic
interference on your mobility scooter.
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 mobile phones. The interference (from radio wave sources) can cause the scooter to release
its brakes, move by itself, or move in unintended directions. It can also permanently damage the scooter
control system. The intensity of the interfering EM energy can be measured in volts per meter (V/m). Each
scooter 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 can achieve 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, mobile phones, and other personal communication devices.
Some mobile phones 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.
3. Long-range transmitters and transceivers such as commercial broadcast transmitters (radio and TV
broadcast antenna towers) and amateur (HAM) radios.
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 mobility scooter.
Scooter Electromagnetic Interference:
Because EM energy rapidly becomes more intense as one moves closer to the transmitting antenna (source),
the EM fields from hand-held radio wave sources (transceivers) are of special concern. It is possible to
unintentionally bring high levels of EM energy very close to the motorized scooter control system while using
these devices. This can affect scooter movement and braking. The warnings listed below are therefore
recommended to prevent possible interference with the control system of the scooter.
Warnings:
Electromagnetic interference (EMI) from sources such as radio and TV stations, amateur radio (HAM)
transmitters, two-way radios, and mobile phones can affect scooters.
Following the warnings listed below should reduce the chance of unintended brake release or scooter
movement which could result in serious injury.
1. Do not operate hand-held transceivers (transmitters-receivers), such as citizens band (CB) radios, or turn
on personal communication devices, such as mobile phones, while the scooter is turned ON.
2. Be aware of nearby transmitters, such as radio or TV stations, and try to avoid coming close to them.
3. If unintended movement or brake release occurs, turn the scooter OFF as soon as it is safe.
4. Be aware that adding accessories or components, or modifying the scooter, may make it more susceptible
to EMI.
There is no easy way to evaluate their effect on the overall immunity of the mobility scooter.
5. Report all incidents of unintended movement or brake release to the distributor listed at the end of this
manual. Note whether there is a source of EMI nearby.
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Instruction Booklet
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