rf exposure info

FCC ID: NHPWLB1402

RF Exposure Info

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FCCID_293322

TRC
Training Research Co., Ltd.
®
255 Nanyang Street, Shijr, Taipei Hsien 221, Taiwan, R.O.C.
Since1985 TEL: 886-2-26935155 FAX: 886-2-26934440

Measurement of MPE

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
EUT : 2.4G USB Wireless LAN

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

Model No. : WLB-1420

FCC ID : NHPWLB1402

Frequency Range : 2.412 GHz ~ 2.462GHz

Support Channel : 11 Channel

Modulation Skill : DBPSK, DQPSK, CCK

Power Type : By the USB interface of computer

Style Interface : USB

Applicant : CAMEO COMMUNICATIONS, INC.
6/F, No.22, Chung Hsin Rd., His-chih, Taipei 221, Taiwan,
R.O.C.

TRC
Training Research Co., Ltd.
®
255 Nanyang Street, Shijr, Taipei Hsien 221, Taiwan, R.O.C.
Since1985 TEL: 886-2-26935155 FAX: 886-2-26934440

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
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
0.3-1.34 614 1.63 100 30
1.34-30 824/f 2.19/f 180/f2 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 44.88 × 1.00
Friis Transmission Formula: S= = = 8.929 × 10 −3 mW / cm 2
4πR 2
4π (20) 2

PG 44.88 × 1.00
Estimated safe separation: R= = = 1.890cm
4π 4π
Remarks: "The safe estimated separation that the user must maintain from the antenna is at least 1.890 cm."

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 (0 / 10) = 1.00

Document Created: 2002-12-20 15:54:24
Document Modified: 2002-12-20 15:54:24

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