User Manual

RF Exposure Compliance Requirements
TSLM UHF Wireless Modem
IC Rule:
RSS 119 Section 9, RSS-102 Section 4.2
Description of Compliance:
The TSLM will be professionally installed in the SCADA (Supervisory Control And Data
Acquisition) market and will be mounted with a fixed RTU (Remote Terminal Unit). A
typical installation would use a maximum gain antenna of 10 dBi mounted on a tower. A
minimum separation distance of more than 1.21 meters must be maintained between the
radiating structure and any person to classify as a mobile under IC MPE regulations.
Note: It is the responsibility of the user to guarantee compliance with the FCC
MPE regulations when operating this device in a way other than described above.
The calculation for the more stringent specification, a General Population/Uncontrolled
Mobile device according to RSS 102 Section 4.2 is shown below:
RF Limits for Devices used by the General Public
Frequency
Range (MHz)
Electric Field
(V/M rms)
Magnetic Field
(A/m rms)
Power Density
(W/m
2
)
Time Average (min)
0.003-1 280 2.19 - 6
1-10 280 / ƒ 2.19 / ƒ - 6
10-30 28 2.19 / ƒ - 6
30-300 28 0.073 2* 6
300-1 500 1.585 ƒ
0.5
0.0042 ƒ
0.5
ƒ / 150 6
1 500-15 000 61.4 0.163 10 6
15 000-150 000 61.4 0.163 10 616 000 / ƒ
1.2
150 000-300 000 0.158 ƒ
0.5
4.21 x 10
-4
ƒ
0.5
6.67 x 10
-5
ƒ 616 000 / ƒ
1.2
Environmental Specification: f(MHz)/(150 W/cm
2
)
406 MHz/(150 MHz mW/cm
2
) = 2.71 W/m
2
(worst case)
S = (PG)/(4πR
2
)
Where:
S = Power Density (W/m
2
)
P = Power input to the antenna (W)
G = Power Gain of the antenna in the direction of interest relative to an isotropic radiator
R = Distance to the center of radiation of the antenna (meters)
Distance Calculation:
R = √((PG)/(4πS))
Typical Antenna Gain: 10.0 dBi 10
(10.0 dBi/10)
= 10.0
Power input to the Antenna: 37dBm = 10
(37dBm/10)
= 5.00 W
R = √((5.00 W*10.0)/(4π*2.71 W/m
2
)) = 1.21 meters (Minimum Distance)