Vislink ARTR, Manual

Page: 6 / 38

Issue No: C Page: 2
Ref: ARTR-ASUM-7001 Copyright © 2017 IMT Ltd, trading as Vislink
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, a maximum power density limit (w) of 1w/m² is to be applied when calculating minimum safe
working distances. 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:

Operators should not stand or walk in front of any antenna, nor should they allow anyone
else to do so.

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 (METRES)
P
T
. G
R
4

.w