MPE Test Report

FCC ID: DWNSITUO-1-ZIG

RF Exposure Info

Download: PDF

FCCID_4434528

EUT: ZIGBEE Report No: 0048-190703-01
Model: SITUO 1 FCC ID:DWNSITUO-1-ZIG

CALCULATIONS

Given
E =  (30 * P * G) / d
and
S = E ^ 2 / 3770
where
E = Field Strength in Volts/meter
P = Power in Watts
G = Numeric antenna gain
d = Distance in meters
S = Power Density in milliwatts/square centimeter
Combining equations and rearranging the terms to express the distance as a function of the remaining
variables yields:
d =  ((30 * P * G) / (3770 * S))

Changing to units of Power to mW and Distance to cm, using:
P(mW) = P (W) / 1000 and
d (cm) =100 * d (m)
yields
d = 100 *  ((30 * (P / 1000) * G) / (3770 * S))
d = 0.282 *  (P * G / S)
where
d = distance in cm
P = Power in mW
G = Numeric antenna gain
S = Power Density in mW/cm^2
Substituting the logarithmic form of power and gain using: P
(mW) = 10 ^ (P (dBm) / 10) and
G (numeric) = 10 ^ (G (dBi) / 10)
yields
d = 0.282 * 10 ^ ((P + G) / 20) /  S Equation (1)
S = 0.0795 * 10 ^ ((P + G)/10)/ d^2 Equation (2)
where
d = MPE distance in cm
P = Power in dBm
G = Antenna Gain in dBi
S = Power Density Limit in mW/cm^2

Equation (1) and the measured peak power is used to calculate the MPE distance.
Equation (2) and the measured peak power is used to calculate the Power density.

Page 17 of 46
Advanced Compliance Laboratory, Inc. 210 Cougar Court, Hillsborough, NJ 08844, tel:(908) 927 9288

EUT: ZIGBEE Report No: 0048-190703-01
Model: SITUO 1 FCC ID:DWNSITUO-1-ZIG

LIMITS

From §1.1310 Table 1 (B),
for Public S = 1.0 mW/cm2
for Professional, S = 5.0 mW/cm2

RESULTS

No non-compliance noted:

For this EUT, P+G=5.83-4=1.83dBm, and d=20cm

Plug all three items into equation (2), yielding,
Power Density Output Antenna] Power Meet min.
Limit Power Gain Density PD Limit
(mV/cm2) (dBm) (dBi) (mW/ cm2)
1.0/5.0 5.83 -4 0.003 Yes

FCC 47 CFR 2.1093 SAR Exclusion Calculation

As per FCC KDB 447498 D01 General RF Exposure Guidance DR03-41372
(All power readings below reflect 1dB addition to account for radio tolerance)

Max. EIRP=1.83+1=2.83dBm, i.e. 0.002W=2mW. Per FCC KDB 447498 D01 General RF
Exposure Guidance v06, Appendix A, SAR Test Exclusion Threshold @2450MHz band for
d=5mm is 10mW. We can conclude that this handheld device is exempt from SAR test.

NOTE: For mobile or fixed location transmitters, the minimum separation distance is 20 cm, even if calculations
indicate that the MPE distance would be less.

Page 18 of 46
Advanced Compliance Laboratory, Inc. 210 Cougar Court, Hillsborough, NJ 08844, tel:(908) 927 9288

Document Created: 2019-09-04 22:09:34
Document Modified: 2019-09-04 22:09:34

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC