User Manual

2.6 FCC MPE Compliance Reports - VHF and UHF
RF Exposure Compliance Requirements
TSLM VHF Wireless Modem
FCC Rule:
1.1307, 1.1310, 2.1091 (b) (d), 2.1093
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 141 cm must be maintained between the
radiating structure and any person to classify as a mobile under FCC 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 section 2.1091(b) and section 1.1310 Note 2 is shown below:
Limits for General Population/Uncontrolled Exposure:
Frequency Range
(MHz)
Electric Field
Strength (V/m)
Magnetic Field
Strength (A/m)
Power Density (mW/cm
2
) Averaging
Time (mins)
0.3-1.34 614 1.63 *(100) 30
1.34-30 824/f 2.19/f *(180/f2) 30
30-300 27.5 0.073 0.2 30
300-1500 --- --- f (MHz)/1500 (MHz) 30
1500-100000 --- --- 1.0 30
Environmental Specification: 0.2 mW/cm
2
S = (PG)/(4πR
2
) (OET Bulletin 65)
Where:
S = Power Density (mW/cm
2
)
P = Power input to the antenna (mW)
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 (cm)
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)
= 5000 mW
R = √((5000mW*10.0)/(4π*0.2 mW/cm
2
)) = 141 cm (Minimum Distance)