2.4.1 ELECTROMAGNETIC INTERFERENCE (EMI) FROM RADIO
WAVE SOURCES
Powered scooters 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 mobile phones. The interference (from radio wave sources) can cause the
powered scooter to release its brakes, move by itself, or move in unintended directions. It can also
permanently damage the powered scooter’s control system. The intensity of the interfering EM energy can be
measured in volts per metre (V/m). Each powered 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 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 scooter model as shipped, with no further
modification, has an immunity level of 20 V/m without any accessories.
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 warning 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 (transmitter-receivers with the antenna mounted directly on the
transmitting unit). Examples include: citizens band (CB) radios, “walkie talkies”, security, fire, and police
transceivers, mobile telephones and other personal communication devices.
Attention
：
Some mobile 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.
3. Long-range transmitters and transceivers, such as commercial broadcast transmitters (radio and TV
broadcast antenna towers) and amateur (HAM) radios.
Attention
：
Other types of hand-held devices, such as cordless phones, laptop computers, AM/FM
radios, TV sets, CD player, 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
scooter.
2.4.2 POWERED SCOOTER ELECTROMAGNETIC INTERFERENCE
(EMI)
Because EM energy rapidly becomes more intense as one moves closer to the transmitting antenna (source),
