RF Exposure Info

FCC ID: XNAWBS01

RF Exposure Info

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FCCID_1158540

FCC ID: XNAWBS01 RF EXPOSURE REPORT REPORT NO.: SA980619L05 MODEL NO.: WBS01 ACCORDING: FCC Guidelines for Human Exposure IEEE C95.1 APPLICANT: Withings ADDRESS: 37bis, rue du General Leclerc -- 92442 Issy-les-Moulineaux Cedex, FRANCE ISSUED BY: Bureau Veritas Consumer Products Services (H.K.) Ltd., Taoyuan Branch LAB ADDRESS: No. 47, 14th Ling, Chia Pau Tsuen, Lin Kou Hsiang, Taipei Hsien 244, Taiwan, R.O.C. TEST LOCATION: No. 19, Hwa Ya 2nd Rd, Wen Hwa Tsuen, Kwei Shan Hsiang, Taoyuan Hsien 333, Taiwan, R.O.C. Report No: SA980619L05 4 Report Format Version 3.0.0

FCC ID: XNAWBS01 RF EXPOSURE MEASUREMENT (MOBILE DEVICE) 1. INTRODUCTION In this document, we try to prove the safety of radiation harmfulness to the human body for our product. The limit for Maximum Permissible Exposure (MPE) specified in FCC 1.1310 is followed. The Gain of the antenna used in this product is measured in a Fully Anechoic Chamber (FAC) calibrated for antenna measurement in ADT, and also the maximum total power input to the antenna is measured. Through the Friis transmission formula and the maximum gain of the antenna, we can calculate the distance, away from the product, where the limit of MPE is reached. Although the Friis transmission formula is a far field assumption, the calculated result of that is an over-prediction for near field power density. We will take that as the worst case to specify the safety range. 2. RF EXPOSURE LIMIT According to FCC 1.1310: The criteria listed in the following table shall be used to evaluate the environmental impact of human exposure to radio-frequency (RF) radiation as specified in 1.1307(b) LIMITS FOR MAXIMUM PERMISSIBLE EXPOSURE (MPE) FREQUENCY ELECTRIC FIELD MAGNETIC FIELD POWER DENSITY AVERAGE TIME 2 RANGE (MHz) STRENGTH (V/m) STRENGTH (A/m) (mW/cm ) (minutes) (A)LIMITS FOR OCCUPATIONAL / CONTROL EXPOSURES 300-1500 … … F/300 6 1500-100,000 … … 5 6 (B)LIMITS FOR GENERAL POPULATION / UNCONTROLLED EXPOSURE 300-1500 … … F/1500 30 1500-100,000 … … 1.0 30 F = Frequency in MHz Report No: SA980619L05 4 Report Format Version 3.0.0

FCC ID: XNAWBS01 3. FRIIS FORMULA Friis transmission formula : Pd = (Pout*G) / (4*pi*r2) where Pd = power density in mW/cm2 Pout = output power to antenna in mW G = gain of antenna in linear scale Pi = 3.1416 R = distance between observation point and center of the radiator in cm If we know the maximum Gain of the antenna and the total power input to the antenna, through the calculation, we will know the MPE value at distance r. Ref.: David K. Cheng, Field and Wave Electromagnetics, Second Edition, Page 640, Eq. (11-133). 4. EUT OPERATING CONDITION The software provided by manufacturer enabled the EUT to transmit and receive data at lowest, middle and highest channel individually. 5. CLASSIFICATION The antenna of this product, under normal use condition, is at least 20cm away from the body of the user. Warning statement to the user for keeping at least 20cm or more separation distance with the antenna should be included in users manual. So, this device is classified as Mobile Device. The radiator is turned off when weight-in measurement occurs. Report No: SA980619L05 4 Report Format Version 3.0.0

FCC ID: XNAWBS01 6. TEST RESULTS 6.1 ANTENNA GAIN The maximum gain measured in is 1.89dBi or 1.55 (numeric). 6.2 MAXIMUM OUTPUT POWER INTO ANTENNA & RF EXPOSURE VALUE AT DISTANCE 20cm: 802.11b DSSS MODULATION: LIMIT OF CHANNEL PEAK POWER POWER PEAK POWER POWER CHANNEL FREQUENCY OUTPUT DENSITY OUTPUT (mW) DENSITY (MHz) (dBm) (mW/CM2) (mW/CM2) 11 2462 115.08 20.61 0.035 1.000 802.11g OFDM MODULATION: LIMIT OF CHANNEL PEAK POWER POWER PEAK POWER POWER CHANNEL FREQUENCY OUTPUT DENSITY OUTPUT (mW) DENSITY (MHz) (dBm) (mW/CM2) (mW/CM2) 6 2437 193.64 22.87 0.060 1.000 Report No: SA980619L05 4 Report Format Version 3.0.0


Document Created: 2009-08-21 14:52:59
Document Modified: 2009-08-21 14:52:59
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