RF Exposure evaluation

FCC ID: 2AR7Q-E01003

RF Exposure Info

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FCCID_4347831

Maximum Permissible Exposure Evaluation An estimation of MPE in this application for product is used to ensure if it complies to the rules of the standard in the regulation list above. Maximum permissible exposure (MPE) refers to the RF energy that is acceptable for human exposure. It is broken down into two categories, Occupational/controlled and General population/uncontrolled. Occupational/controlled limits apply in situations in which persons are exposed as a consequence of their employment provided those persons are fully aware of the potential for exposure and can exercise control over their exposure. Limits for occupational/controlled exposure also apply in situations when an individual is transient through a location where occupational/controlled limits apply provided he or she is made aware of the potential for exposure. General population/uncontrolled exposures apply in situations in which the general public may be exposed, or in which persons that are exposed as a consequence of their employment may not be fully aware of the potential for exposure or can not exercise control over their exposure. We analysis if it comply with the limits for General population/uncontrolled exposure. The FCC’s MPE limits for field strength and power density are given in 47CFR 1.1310(Table below).These limits are generally based on recommended exposure guidelines published by the National Council on Radiation Protection and Measurements (NCRP), and also partly based on guidelines recommended by the American National Standards Institute (ANSI) in Section 4.1 of ANSI/IEEE C95.1. Page 1 of 3

Table: Limits For Maximum Permissible Exposure (MPE) (A) Limits for Occupational/controlled Exposure Power Averaging Time Frequency Electric Field Magnetic Field Density (minute)|E|2,|H|2 or Range(MHz) Strength(E)(V/m) Strength(H)(A/m) (S)(mW/cm2) S 0.3-3.0 614 1.63 (100)* 6 3.0-30 1842/f 4.89/f (900/f2)* 6 30-300 61.4 0.163 1.0 6 300-1500 -- -- f/300 6 1500-100,000 -- -- 5 6 (B) Limits for General Population/uncontrolled Exposure Power Averaging Time Frequency Electric Field Magnetic Field Density (minute)|E|2,|H|2 or Range(MHz) Strength(E)(V/m) Strength(H)(A/m) (S)(mW/cm2) S 0.3-1.34 614 1.63 (100)* 30 1.34-30 824/f 2.19/f (180/f)* 30 30-300 27.5 0.073 0.2 30 300-1500 / / f/1500 30 1500-100,000 / / 1.0 30 f=frequency in MHz *Plane-wave equivalent power density A rough estimation of the expected exposure in power flux density on a given point can be made with the following equation: P*G S= 4π*R2 Where: S = power density P = power input to the antenna G = numeric gain of the antenna in the direction of interest relative to an isotropic radiator Page 2 of 3

R= distance to the centre of radiation of the antenna EIRP = P*G The antenna of the product, under normal use condition is at least 20 cm away from the body of the user. Warning statement to the user for keeping at least 20cm separation distance and the prohibition of operating to a person has been printed on the user’s manual. Therefore, the S of the device is calculated with R=20cm, and if it is below the limit S, then we can conclude the device complies with the rules. The worst case (refer to report FCC18120074A-U-NII) is below: For 2.4G Wi-Fi: Antenna Gain: 2.65dBi TYPE Max. Max. Conducted R S MPE Limit Conducted Conclusion Power (cm) (mW/cm2) (mW/cm2) Power (dBm) (mW) Antenna:1 19.97 99.31 20 0.03637 Antenna:2 19.59 90.99 20 0.03332 Antenna 1 + 1.00 PASS Antenna 2 22.79 190.11 20 0.06962 Note:*- based on the maximum tune-up tolerance limit declared by manufacturer. 0.06962<1.00 So the SAR report is not required. Page 3 of 3


Document Created: 2019-03-25 10:16:24
Document Modified: 2019-03-25 10:16:24
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