Otto Bock SKIPPI, Руководство по обслуживанию

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Safety instructions
Skippi Ottobock | 11
2.7 Effects of electromagnetic interference
WARNING
Risks of injury and product damage due to electromagnetic interference.
It is very important that
you read the information pertaining to the possible effects of electromagnetic interference on your
power wheelchair.
2.7.1 General information on electromagnetic interference
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Power wheelchairs may be susceptible to electromagnetic interference. This is the interfering
electromagnetic energy emitted by radio equipment such as radio and television stations,
amateur radio transmitters (HAM), two-way radios, and cellular phones.
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The interference (from radio wave sources) can cause the power wheelchair to release its
brakes, move by itself, or move in unintended directions.
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It can also permanently damage the power wheelchair control system.
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The intensity of the interfering EM energy can be measured in volts per meter (V/m). Each
power 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 provides effective protection
from the more common sources of radiated EMI.
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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.
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The sources of radiated EMI can be broadly classified into three types:
– Handheld 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.
INFORMATION
Some cellular telephones and similar devices transmit and receive signals while they are ON, even
when not being used;
– Medium-range mobile transceivers, such as those used in police cars, fire trucks, ambu-
lances, and taxis. These usually have the antenna mounted on the outside of the vehicle;
– Long-range transmitters and transceivers, such as commercial broadcast transmitters
(radio and TV broadcast antenna towers) and amateur (HAM) radios.
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Because EM energy rapidly becomes more intense as one moves closer to the transmitting
antenna (source), the EM fields from handheld radio wave sources (transceivers) are of special
concern. It is possible to unintentionally bring high levels of EM energy very close to the po-
wer wheelchair's control system while using these devices. This can affect power wheelchair
operation and braking.