Guide DF Integration
Issue No: A
Page: 6
Ref: DragonFly Installation Guide
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:
Table 1-1
Minimum Safe Distance Overview Table
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)
P
T
. G
R
4
.w
