Siemens SD 270 Operating Manual page 73

Recommended separation distances between portable and mobile
RF communications equipment and the SD 270 Audiometer
The SD 270 Audiometer is intended for use in an electromagnetic envi-
ronment in which radiated RF disturbances are controlled. The customer
or the user of the SD 270 Audiometer can help prevent electromagnetic
interference by maintaining a minimum distance between portable and
mobile RF communications equipment (transmitters) and the SD 270
Audiometer as recommended below, according to the maximum output
power of the communications equipment.
Rated maxi-
mum output
power of trans-
mitter
W
0.01
0.1
1
10
100
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 80MHz and 800MHz, the separation distance for the higher
frequency range applies.
NOTE 2: These guidelines may not apply in all situations. Electromagne-
tic propagation is affected by absorption and reflection from structures,
objects and people.
Separation distance according to frequency of
150 kHz to 80
MHz
d = 1.2√P
0.12
0.38
1.2
3.8
12
transmitter
m
80 MHz to 800
MHz
d = 1.2√P
0.12
0.38
1.2
3.8
12
800 MHz to 2.5
GHz
d = 2.3√P
0.23
0.73
2.3
7.3
23
73