RF Exposure Info

FCC ID: NHPWLG1200

RF Exposure Info

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FCCID_392928

Measurement of Maximum Permissible Exposure －－－－－－－－－－－－－－ 1/4

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

Granted FCC ID : NHPWLG1200

Product name : Wireless PCI Adapter

Model name : as Appendix A of Test Report
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 : 2.412 GHz ~ 2.462GHz
Supported Channel : 11 Channels
Modulation Skill : DBPSK, DQPSK, CCK, OFDM
Power Type : Powered by PCI interface of the client’s device

FCC ID: NHPWLG1200
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Measurement of Maximum Permissible Exposure －－－－－－－－－－－－－－ 2/4

3. Limits for Maximum Permissible Exposure (MPE)
Frequency Range Electric Field Magnetic Filed Power Density (S) Averaging Time
Strength Strength (H) |E| 2, |H| 2 or S
(MHz) (V/m) (A/m) (mW/cm2) (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

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

3.1 IEEE 802.11b, Lowest CH
PG 62.661 ×1.514
Friis Transmission Formula: S= = = 0.0189 mW / cm 2
4πR 2
4π (20) 2

PG 62.661 × 1.514
Estimated safe separation: R= = = 2.747cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 2.747cm."

3.2 IEEE 802.11b, Middle CH
PG 69.183 × 1.514
Friis Transmission Formula: S= = = 0.0385mW / cm 2
4πR 2
4π( 20) 2
PG 69.183 ×1.514
Estimated safe separation: R= = = 2.887cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 2.887cm."

FCC ID: NHPWLG1200
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Measurement of Maximum Permissible Exposure －－－－－－－－－－－－－－ 3/4

3.3 IEEE 802.11b, Highest CH
PG 67.453 × 1.514
Friis Transmission Formula: S= = = 0.0203mW / cm 2
4πR 2
4π( 20) 2
PG 67.453 ×1.514
Estimated safe separation: R= = = 2.8507cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 2.851cm."

3.4 IEEE 802.11g, Lowest CH
PG 118.032 ×1.514
Friis Transmission Formula: S= = = 0.03555mW / cm 2
4πR 2
4π (20) 2

PG 118.0328 × 1.514
Estimated safe separation: R= = = 3.771cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 3.771cm."

3.5 IEEE 802.11g, Middle CH
PG 127.938 × 1.514
Friis Transmission Formula: S= = = 0.0385mW / cm 2
4πR 2
4π (20) 2

PG 127.938 × 1.514
Estimated safe separation: R= = = 3.926cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 3.926cm."

3.6 IEEE 802.11g, Highest CH
PG 125.314 ×1.514
Friis Transmission Formula: S= = = 0.03774 mW / cm 2
4πR 2
4π (20) 2

PG 125.314 × 1.514
Estimated safe separation: R= = = 3.8856cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 3.886cm."

FCC ID: NHPWLG1200
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Measurement of Maximum Permissible Exposure －－－－－－－－－－－－－－ 4/4

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 (1.8 / 10) = 1.514

FCC ID: NHPWLG1200
Training Research Co., Ltd., TEL: 886-2-26935155, Fax: 886-2-26934440

Document Created: 2004-01-30 09:39:26
Document Modified: 2004-01-30 09:39:26

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