31
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 meters
(m). Field strengths from fixed
RF transmitters, as determined
by an electromagnetic site
survey
a
should be less than the
compliance level in each
frequency range
b
. Interference
may occur in the vicinity of
equipment marked with the
following symbol:
Note 1: From 80MHz to 800MHz, 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/cordless) telephones and land mobile radios, amateur radio, AM and
FM radio broadcast and TV broadcast cannot be predicted theoretically with
accuracy. To assess the electromagnetic environment due to fixed RF
transmitters, an electromagnetic site survey should be considered. If the
measured field strength in the location in which the oxygen concentrator is
used exceeds the applicable RF compliance level above, the oxygen
concentrator should be observed to verify normal operation. If abnormal
performance is observed, additional measures may be necessary, such as
re-orienting or relocating the oxygen concentrator.
b
Over the frequency range 150kHz to 80MHz, field strengths should be less
than 3V/m.
9.4
Recommended separation distances between portable and
mobile RF communications equipment and the concentrator
The medical oxygen concentrator is intended for use in the electromagnetic
environment specified below. The customer or the user of the concentrator
can help prevent electromagnetic interference by maintaining a minimum