Widex USB LINK, User Instructions

Page: 26 / 36

26
Immunity Test IEC 60601
Test level
Compliance
level
Electromagnetic
environment – guidance
radiated rF
IEc 61000-4-3
3 V/m
80 mHz to
2.5 GHz
3 V/m d = 1.2
√
P
80 mHz to 800 mHz
d = 2.3
√
P
800 mHz to 2.5 GHz
where P is the maximum output
power rating of the transmitter
in watts (W) according to the
transmitter manufacturer and d
is the recommended separation
distance in metres (m).
Field strengths from fixed rF
transmitters, as determined by
an electromagnetic site survey
a
,
should be less than the compli-
ance level in each frequency
range
b
.
Interference may occur in the vi-
cinity of equipment marked with
the following symbol:
noTE 1 At 80 mHz and 800 mHz, the higher frequency range applies
noTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is
affected by absorption and reflection from structures, objects and people.
a. Field strengths from fixed transmitters, such as base stations for radio (cellular/cord-
less) telephones and land mobile radios, amateur radio, Am and Fm radio broadcast and
TV broadcast cannot be predicted theoretically with accuracy. To assess the electromag-
netic environment due to fixed rF transmitters, an electromagnetic site survey should be
considered. If the measured field strength in the location in which the USB Link is used
exceeds the applicable rF compliance level above, the USB Link should be observed to
verify normal operation. If abnormal performance is observed, additional measures may
be necessary, such as re-orienting or re-locating the USB Link.
b. over the frequency range 150 kHz to 80 mHz, field strengths should be less than
3 V/m.