Template Operators Manual
General Information
Issue No: 1
Page: 9
Ref: INHG-ASUM-70XX
Copyright © 2020 IMT and Vislink are Vislink Technologies Inc. companies
1.4.
Health & Safety
Exposure to Non-Ionizing (RF) Radiation/Safe Working Distances
The safe working distance from a transmitting antenna may be calculated
from the relationship:
D =
in which D = safe working distance (meters)
PT = transmitter or combiner power output (watts)
GR = antenna gain ratio = anti log (gain dBi ÷10)
w = Maximum allowed power density (watts/square meter)
The RF power density value is determined by reference to safety
guidelines for exposure of the human body to non-ionizing radiation. It is
important to note that the guidelines adopted differ throughout the world
and are from time-to-time re-issued with revised guidelines. For Vislink
use, when calculating minimum safe working distances, apply a maximum
power density limit (w) of 1w/m². Appendix A refers.
WARNING: Any transmitting equipment, radiating power at frequencies of
100 kHz and higher, has the potential to produce thermal and
athermal effects upon the human body.
To be safe:
a.
Operators should not stand or walk in front of any antenna, nor should they
allow anyone else to do so.
b.
Operators should not operate any RF transmitter or power amplifier with any of
its covers removed, nor should they allow anyone else to do so.
Worked examples:
Antenna
Transmitter Power
Type
Gain (dBi) Gain Ratio
2W
4W
10W
30W
OMNI
4
2.5
1
1
1.5
2.5
HELIX
20
100
4
5.6
9
15.5
PARABOLIC
DISH
35
3,162
22.5
32
50
87
MINIMUM SAFE DISTANCE (METERS)
Table 1-1
Minimum Safe Distance Overview Table
P
T
. G
R
4
.w
