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Recommended separation distance between portable and mobile
RF communications equipment and the R27A/R37A
The R27A/R37A audiometer is intended for use in an electromagnetic environment in which radiated
RF disturbances are controlled. The customer or the user of the R27A/R37A can help prevent
electromagnetic interference by maintaining a minimum distance between portable and mobile RF
communications equipment (transmitters) and the R27A/R37A as recommended below, according to
the maximum output power of the communications equipment.
Rated maximum
output power of
transmitter W
Separation distance according to frequency of transmitter m
150 Khz to 80 MHz
d = 1,2√P
80 MHz to 800 MHz
d = 1,2√P
800 MHz to 2,5 GHz
d = 2,3√P
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
7.2
100 12
12
23
For transmitters rated at a maximum output power not listed above, the recommended separation
distance d in meters (m) can be estimated using the equation applicable to the frequency of the
transmitter, where P is the maximum output 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 aected by
absorption and reection from structures, objects and people.