RF EXPOSURE

FCC ID: SLEW341

RF Exposure Info

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FCCID_792198

Measurement of Maximum Permissible Exposure ---------------------------------------- 1/3

Measurement of Maximum Permissible Exposure
1. Foreword
In adopt with the Human Exposure IEEE C95.1, and according to the FCC 1.1310. The
Maximum Permissible Exposure (MPE) is obligated to measure in order to prove the safety
of radiation harmfulness to the human body.

The Gain of the antenna used is measured in an Anechoic chamber. The maximum total
power to the antenna is to be recorded. By adopting the Friis Transmission Formula and
the power gain of the antenna, we can find the distance right away from the product, where
the limit of the MPE is.

2. Description of EUT
FCC ID : SLEW341

Product name : RISC-based Ready-to-Run Wireless Embedded Computer

Model : ThinkCore W341, ThinkCore W341-LX

Classification : Mobile Device
(i) Under normal use condition, the antenna is at least 20cm
away from the user;
(ii) Warning statement for keeping 20cm separation distance
and the prohibition of operating next to the person has been
printed in the user’s manual

Frequency Range : 5.150GHz ~ 5.250GHz

Operating Frequency : 5.180GHz ~ 5.240GHz

Supported Channel : 13 Channels

Modulation Skill : DBPSK, DQPSK, CCK, OFDM
Power Type : Powered by the switching adapter,

Manufacture: BALANCE ELECTRONICS CO., LTD.
Model: GPSA-1200125
I/P: 100 ~ 240VAC ~ 50/60Hz 0.5A
O/P: 12VDC 1.2A.
Primary: 182cm length, non-shielded, without ferrite core
Secondary: 186cm length, non-shielded, without ferrite core

Applicant: Moxa Technologies Co., Ltd.
FCC ID: SLEW341, FCC Part 15 Subpart E for UNII
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Measurement of Maximum Permissible Exposure ---------------------------------------- 2/3

3. Limits for Maximum Permissible Exposure (MPE)
Frequency Electric Field Magnetic Filed Power Density (S) Averaging Time
Range Strength (V/m) Strength (H) (mW/cm2) |E|2, |H|2 or S
(MHz) (A/m) (minutes)
(A) Limits for Occupational/Controlled Exposure
0.3-3.0 614 1.63 100 6
2
3.0-30 1842/f 4.89/f 900/f 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
0.3-1.34 614 1.63 100 30
2
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
[The EUT is tested in transmit and receive modes and in the first, middle and the last channel separately. The
following shows only our observation have the greatest emissions.]

According to OET BULLETIN 56 Fourth Edition/August 1999, Equation for Predicting RF Fields:

PG 26.12 × 1.585
Friis Transmission Formula: S = = = 0.0082mW / cm 2
4πR 2
4π (20) 2

PG 26.12 × 1.585
Estimated safe separation: R = = = 1.82cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 4.73cm"

Where: S = power density (in appropriate units, e.g. mW/cm2)
P = power input to the antenna (in appropriate units, e.g., 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 (appropriate units, e.g., cm)

The Numeric gain G of antenna with a gain specified in dB is determined by:
G = Log -1 ( dB antenna gain / 10 )
G = Log -1 (2.00 / 10) = 1.585

Applicant: Moxa Technologies Co., Ltd.
FCC ID: SLEW341, FCC Part 15 Subpart E for UNII
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Measurement of Maximum Permissible Exposure ---------------------------------------- 3/3

Appendix

Antenna Specification

Applicant: Moxa Technologies Co., Ltd.
FCC ID: SLEW341, FCC Part 15 Subpart E for UNII
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Document Created: 2007-04-24 11:10:15
Document Modified: 2007-04-24 11:10:15

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