RF Exposure Evaluation
According to FCC 1.1310: The criteria listed in the following table shall be used to evaluate the environment impact of human exposure to radio frequency(RF) Radiation as specified in §1.1307(b)
FCC ID: 2AOKB-T8170
EUT Specification
| EUT | eufy Security C220 Smart Lock |
| Frequency band (Operating) | ☐ WLAN: 2.412GHz ~ 2.462GHz ☐ WLAN: 5.18GHz ~ 5.24GHz ☐ WLAN: 5.745GHz ~ 5.825GHz ☑ Others: Bluetooth: 2402-2480MHz |
| Device category | ☐ Portable (<20cm separation) ☑ Mobile (>20cm separation) ☐ Others |
| Exposure classification | ☐ Occupational/Controlled exposure (S = 5mW/cm2) ☑ General Population/Uncontrolled exposure (S=1mW/cm2) |
| Antenna diversity | ☐ Single antenna ☐ Multiple antennas ☐ Tx diversity ☐ Rx diversity ☐ Tx/Rx diversity |
| Antenna gain (Max) | WIFI 2.4G: 3.39dBi |
| Evaluation applied | ☐ MPE Evaluation ☑ SAR Evaluation |
Limits for Maximum Permissible Exposure(MPE)
| Frequency Range(MHz) | Electric Field Strength(V/m) | Magnetic Field Strength(A/m) | Power Density(mW/cm²) | Average Time |
|---|---|---|---|---|
| (A) Limits for Occupational/Control Exposures | ||||
| 300-1500 | -- | -- | F/300 | 6 |
| 1500-100000 | -- | -- | 5 | 6 |
| (B) Limits for General Population/Uncontrol Exposures | ||||
| 300-1500 | -- | -- | F/1500 | 6 |
| 1500-100000 | -- | -- | 1 | 30 |
Friis transmission formula
Pd=(Pout*G)\/(4*pi*R2)
Where
Pd= Power density in mW/cm²
Pout=output power to antenna in Mw
G= gain of antenna in linear scale
Pi=3.1416
R= distance between observation point and center of the radiator in cm
Pd the limit of MPE, 1mW/cm2. If we know the maximum gain of the antenna and total power input to the antenna, through the calculation, we will know the distance where the MPE limit is reached.
Max Measurement Result
| Operating Mode | Measured Power (dBm) | Tune up tolerance (dBm) | Max. Tune up Power (dBm) | Antenna Gain (dBi) | Power density at 20cm (mW/cm2) | Power density Limits (mW/cm2 ) | |
|---|---|---|---|---|---|---|---|
| WIFI 2.4G | 21.70 | 21.70 | ±1 | 22.7 | 3.39 | 0.0809 | 1 |
Result: No Standalone SAR test is required.
