Updated RF exposure Info

FCC ID: SK9ITR900-1

RF Exposure Info

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FCCID_1299211

RF Exposure Considerations for Itron 900 MHz FHSS Radio Module The following radio modules will be used in product that will result in co-location of the antennas for the modules: Company FCC ID Description Pout Max dBm Antenna Gain Max dBi Tropos Networks P9J-2411 2.4 GHz module 28.5 7.4 Tropos Networks P9J-5805 5.8 GHz module 26.4 19 Itron Electricity Meters SK9ITR900-1 902 MHz module 26.2 3 RFx CALCULATION FOR MULTIPLE CO-LOCATED TX SOURCES The following relationships between power density (S), distance from antenna (d meters), transmitter field strength ( E v/m), transmitter power (P, watts) and antenna gain (G, numeric) are used to determine MPE for each transmitter: E2/3770 = S, mW/cm2 E, V/m = (Pwatts*Ggain*30).5/d, meters MPE d,m = ((Pwatts*G*30)/3770*S))0.5 Pwatts*Ggain = 10(PdBm-30+GdBi)/10) S@dist2 = S@dist1*(dist1/dist2)2 Per OET 65, the allowed cumulative exposure limit at a given point from three transmitters operating at different frequencies is Sf1/Sf1limit + Sf2/Sf2limit + Sf3/Sf3limit < 1, where Sf1 = power density at a given point for transmitter operating at F1 MHz Sf2 = power density at a given point for transmitter operating at F2 MHz Sf3 = power density at a given point for transmitter operating at F3 MHz Sf1limit = power density limit at frequency F1 (from Table 1 in Appendix A of OET 65) Sf2limit = power density limit at frequency F2 (from Table 1 in Appendix A of OET 65) Sf3limit = power density limit at frequency F3 (from Table 1 in Appendix A of OET 65) At a distance of 56.4 cm, the weighted cumulative RF exposure is 99.9% of the allowed maximum. The MPE distance that will be reported in final product manuals that use the above listed combination of radios and maximum antenna gains will be 57 cm. The spreadsheet with the calculations is attached.

Tropos/Itron Module Mfr FCC ID IC Certification 2.4 GHz Tropos P9J-2411 4751A-2411 5.8 GHz Tropos P9J-5805 4751A-5805 902 MHz Itron SK9ITR900-1 864G-ITR9001 Calculate mW/cm2 here. Enter frequency in MHz: Calculation of Limits from 1.1310 Table 1 S1 for 2.4 GHz 1.00 maximum Manual RFx Dist: 56.4 cm Controlled Uncontrolled S2 for 902 MHz 0.60 maximum Ave 6 min Ave 30 min S3 for 5805 MHz 1.00 maximum F(MHz) Actual F, MHz Occ, mW/c2 Gen, mW/cm2 0.3-3 0.5 100.0 100.0 Max RF Power TX Antenna MPE distance S, mW/cm2 S, mW/cm2 at Comment 1 Comment 2 3.0 - 30.0 5 180.0 36.0 P, dBm G, dBi cm at 20 cm dist 56.4 30.0-300 55 1.0 0.2 cm 300-1500 902 3.0 0.60 2.4 GHz Duty 28.5 7.40 17.6 0.77 0.10 Cycle = 100% Max eirp = 36 dBm 1500-100000 5805 5.0 1.0 902MHz Duty 26.2 3.0 10.4 0.16 0.02 Cycle = 100% 5805MHz Duty 26.4 19.0 52.5 6.90 0.87 Cycle 100% Enter P(mW) Equivalent dBm Enter dBm Equivalent Watts % 2.4 GHx RFx 10% % 902 MHz RFx 3% %5.8 GHz RFx 87% Total RFx 99.9% Basis of Calculations: 555 27.44 29.52 895.4 E^2/3770 = S, mW/cm2 E, V/m = (Pwatts*Ggain*30)^.5/d, meters d = ((Pwatts*G*30)/3770*S))^0.5 Pwatts*Ggain = 10^(PdBm-30+GdBi)/10) S@dist2 = S@MPEdist(MPE/dist2)^2 NOTE: For mobile or fixed location transmitters, minimum separation distance is for FCC compliance is 20 cm, even if calculations indicate MPE distance is less


Document Created: 2010-06-17 15:29:05
Document Modified: 2010-06-17 15:29:05
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