Karma KP-31, Owner'S Manual

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8
3. EMI/RFI
This section provides the user with basic information about the
problems with EMI, known sources of EMI and protective measures
either to reduce the possibility of exposure or to minimize the degree of
exposure. This section also shows some conditions in which unexpected
or erratic wheelchair movements may occur.
CAUTION
●It is very important that you read this information regarding the
possible effects of electromagnetic interference on your powered
KARMA wheelchair.
3.1 Electromagnetic Interference From Radio Wave Sources
3.1.1 Powered vehicles may be susceptible to electromagnetic interference
(EMI), which is interfering electromagnetic energy (EM) emitted from
sources such as radio stations (Radio Frequency Interference), TV
stations, amateur radio (HAM) transmitters, two-way radios, and cellular
phones. The interference (from radio wave sources) can cause the
powered vehicle to release its brakes, move by itself, or move in
unintended directions. It can also permanently damage the powered
vehicle's control system. The intensity of the interfering EM energy can
be measured in volts per meter (V/m). Each powered vehicle can resist
EMI up to a certain intensity. This amount of resistance 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. This powered vehicle
model, with no further modification, has an immunity level of 20 V/m
without any accessories.
3.1.2 There are a number of sources of relatively intense electromagnetic
fields in our everyday environment. Some of these sources are obvious
and easy to avoid. Others are not apparent and exposure could be