Motorola Motorola PTP 250, User Manual, Page: 114 / 236

Compliance with safety standards Chapter 4 Reference information
phn-2182_002v000
4-24
May 2011
Power density exposure limit
Install the radios for the PTP 250 families of PTP wireless solutions so as to provide
and maintain the minimum separation distances from all persons.
The applicable power density exposure limit from the standards (see Human exposure
to radio frequency energy on page 4-23 ) is 10 W/m
2
for RF energy in the 5.4 GHz and
5.8 GHz frequency bands.
Calculation of power density
NOTE
The following calculation is based on the ANSI IEEE C95.1-1991 method, as
that provides a worst case analysis. Details of the assessment to
EN50383:2002 can be provided, if required.
Peak power density in the far field of a radio frequency point source is calculated as
follows:
Where: Is:
S
power density in W/m
2
P
maximum average transmit power
capability of the radio, in W
G
total Tx gain as a factor, converted
from dB
d
distance from point source, in m.
Rearranging terms to solve for distance yields:
2
4
.
d
G P
S
S
S
G P
d
. 4
.
S