Product Manual

29
IMPORTANT
IMPORTANT INFORMATION
Low Power Non-Ionising Radio Transmission and Safety
Concern has been expressed in some quarters that low power radio frequency transmission may constitute
a health hazard. The transmission characteristics of low power radio devices is a highly regulated environment
for the assurance of safe use.
There are strict limits on continuous emission power levels and these are reflected in the testing specifications
that the products are approved to. These type approval limits are reflected in the product specifications required
for a typical geographic area such as those for the EU (ETS300:440), for the USA (FCC part 15c) and for Australia/
New Zealand (AS/NZS 4268). The limits adopted in these specifications are typically replicated in many other
localized specifications.
The level of safe human exposure to radio transmission is given by the generally accepted guidelines issued by
the International Commission on Non-Ionizing Radiation Protection (ICNIRP). This body has issued guidance
for limiting exposure to time-varying electric, magnetic and electromagnetic fields (up to 300 GHz) which are
quoted below.
Note 1 Values are calculated conversions for comparison purposes.
Note 2 Other equivalent limits include; Medical Research Council Limit of 10mW/cm
2
, IACP limit of 5mW/cm
2
(at 5cm) and
UK CAST limit of 5mW/cm
2
Note 3 Calculation is made on the assumption antenna is a point source therefore the actual value is likely to be significantly
less than that quoted. Note that a theoretical max level at a 5cm distance (which gives 0.318mW/cm
2
) is at a point in
the field where the radar beam is not properly formed.
Note 4 Comparison for product model 317 operating in the band typically 24.050GHz to 24.250GHz
From the table it can be seen that it is extremely unlikely that a potentially hazardous situation could occur owing
to the use of such low power devices.
It is considered to be good practice not to subject humans to radiation levels higher than is necessary. In a works
environment where multiple equipment on soak test are to be encountered then it is considered good practice to
contain the equipment in an appropriate enclosure lined with radar absorbing material.
Radar and ICNIRP limit comparison Typical Informative Limits for Radar
Transmission Approval
Radar
Transmitted
Level (Note 4)
ICNIRP Limit
(Table 6)
Exposure
Margin ETS300:440 FCC (part15c) AS/NZS 4268
Power
(mW EIRP)
<100mW
(<20dBm)
N/A N/A 100mW
(20dBm)
1875mW
(Note 1)
100mW
(20dBm)
Max Power
Density
(mW/cm2)
3.18µW/cm2
at 50cm
(Note 3)
<50W/m2
(5mW/cm2)
(Note 2)
0.064% N/A N/A N/A
Field Strength
(V/m) at 3m
<0.58V/m
(5.8mV/cm)
(Note 1)
<137V/m
(1370mV/cm) 0.42%
0.58V/m
(5.8mV/cm)
(Note 1)
2500mV/m
(25mV/cm)
0.58V/m
(5.8mV/cm)
(Note 1)