21
RF disturbances are controlled. The customer or the user of the Fetal Doppler can help
prevent electromagnetic interference by maintaining a minimum distance between portable
and mobile RF communications equipment (transmitters) and the Fetal Doppler as
recommended below, according to the maximum output power of the communications
equipment.
Rated
maxim
um
output
power
of
transmi
tter
W
Separation distance according to frequency of transmitter m
150 kHz to
80 MHz
80 MHz to
800 MHz
800 MHz to 2,5 GHz
0.01
0.12 0.12 0.23
0.1
0.38 0.38 0.73
1
1.2 1.2 2.3
10
3.8 3.8 7.3
100
12 12 23
For transmitters rated at a maximum output power not listed above, the recommended
separation distance d in metres (m) can be estimated using the equation applicable to the
frequency of the transmitter, where P is the maximum output power rating of the transmitter
in watts (W) according to the transmitter manufacturer.
NOTE 1 At 80 MHz and 800 MHz, the separation distance for 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.