RF Exposure Report

FCC ID: LLB10001

RF Exposure Info

Download: PDF
FCCID_1467380

ACLARA RF SYSTEMS Former HEXAGRAM Inc. 30400 Solon Road . Solon, OH 44139 440-528-7200 Wednesday, April 26, 2011 LLB10001 RF Exposure calculations Based on FCC 1.1307 & 2.1091, FCC OET Bulletin 65. (1) Categorically Exclusion from RF exposure Evaluation: According to FCC regulations, RF exposure evaluation is Categorically Excluded if transmitter’s operation frequency is less than 1.5 GHz and ERP is less than 1.5 watt. (2) Absolute Maximum specifications of LLB10001 transmitter • Operational frequency band 450 MHz to 470 MHz. • The LLB10001 transmitter is measured for Max RF Power = .0.229 W. • Absolute Maximum transmission time (duration) for any Hexagram transmitters does not exceed 100 mS (0.10second). • Transmission period – Absolute maximum is 4 transmissions per hour. • All Hexagram Transmitters utilize FSK modulation. (3) Average RF Power Calculation: FCC regulations on permissible RF exposure are not based on peak envelope power (PEP), but on average power (P_ave) over a 30-minute time period for uncontrolled environments. As mentioned in (2), during any 30 minute Hexagram MTU can transmit only two times. Duration = 0.10 second. With maximum RF radiation equal to .229 W, the Average RF Power over 30 minutes is: P_ave (worst case) at 30 minute = .229 W*2* [0.10sec/((30*60)sec)] = 0.254mW (4) Maximum Radiated Power Density prediction (S): To predict power density (S) at distance R=20 cm from transmitter with P_ave = .393mW, next formula is used: S = P_ave/(4*(PI)*R^2) For the worst of the worst worst-case prediction of power density at or near a transmitter surface let’s use: S = P_ave/((PI)*R^2) = 0.254mW/(4*3.14*20cm*20cm) = 50.53 uW/cm^2. This is the worst case of the near field power density of LLB10001 transmitter. (5) Maximum Permissible Exposure (MPE) from LLB10001: AS FCC require, the maximum permissible exposure for general public in “uncontrolled situation” at 20 cm is: MPE = 460MHz/1500 = 1.228 mW/cm^2. By comparing results in (4) and (5), S=50.53 uW/cm^2 < MPE=0.440 mW/cm^2. We see that LLB10001 fully complies with RF safety at a distance of 20 cm. Sincerely, Siva Jambulingam Principal Engineer 440-528-7200 sjambulingam@aclara.com


Document Created: 2011-05-11 16:16:43
Document Modified: 2011-05-11 16:16:43
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC