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Elektromagnetische Felder

Overview of the sources of high-frequency fields

In everyday life, we experience high-frequency fields in a variety of applications, for example in:

  • mobile communications
  • radio and television
  • cordless phones
  • WLAN and Bluetooth.

The following table lists the most important sources of high-frequency fields with the key parameters, including the specific applicable limit or reference values.

Sources of high-frequency fields
SourceFrequencyTypical transmitter powerMeasurement distance from the transmitter antenna/ typical level of exposureReference value / limit valueLimit values
for immissions averaged
quadratically
over 6-minute
intervals
(26th BImSchV)
Radio stations-

Medium wave

526 kHz  - 1,6 MHz

1.8 MW 50 m / 450 V/m83 V/m, 27 µT87 - 69 V/m, 1.38 - 0.45 A/m
300 m / 90 V/m
Limit value is complied with starting from about 350 metres in maximum radiation direction*

Shortwave

4 MHz - 26 MHz

750 kW 50 m  / 121.5 V/m 83 V/m, 27 µT (only for f ≤ 10 MHz) 43.5 – 28
V/m, 0.18 –
0.073 A/m
220 m / 27.5 V/m

Limit value is complied with starting from about 220 metres in maximum radiation direction*

VHF

88 MHz - 108 MHz ≤ 100 kW ca. 1.5 km / < 0.05 W/m2not applicable28 V/m, 0.073
A/m
Limit value is complied with starting from about 250 metres in maximum radiation direction*
Television stations-
VHF174 MHz - 223 MHz ≤ 300 kW ca. 1.5 km/ < 0.02 W/m2 28 V/m or 2 W/m228 V/m, 0.073
A/m
(corresponds to about 2 W/m2)
Limit value is complied with starting from about 150 metres in maximum radiation direction*
UHF 470 MHz - 838 MHz ≤ 5 MW ca. 1.5 km < 0.005 W/m230 - 40 V/m
or
2.3 - 4.2 W/m2
30 - 40 V/m,
0.08 – 0.11
A/m
(corresponds to about
2.3 - 4.2
W/m2
Limit value is complied with starting from about 75 metres in maximum radiation direction*
Mobile communications-
GSM 900
Base station 890 MHz
- 915 MHz
4 channels, 15 W each** 50 m / 0.06 W/m241 - 43 V/m or 4.5  - 4.8 W/m241.0 - 41.6 V/m, 0.110 - 0.111 A/m
(corresponds to about 4.5 W/m2)
Limit value is complied with starting from few metres in maximum radiation direction*
Mobile phone935 MHz - 960 MHzmax 2 W as peak value
GSM 1800
Base station1710 MHz -
1785 MHz
4 channels, 10 W each ** 50 m / 0.04 W/m256.8 - 58.1 V/m or 8.6 - 8.9 W/m256.8 - 58.1 V/m, 0.153 - 0.156 A/m  (corresponds to 8.6 - 9.1 W/m2)
Limit value is complied with starting from few metres in maximum radiation direction*
Mobile phone1805 MHz -
1880 MHz
max 1 W as peak value
UMTS
Base station2110 MHz -
2170 MHz
2 channels, 20 W each** 50 m / 0.04 W/m261 V/m or 10 W/m261 V/m, 0.16 A/m (corresponds to about
10 W/m2)
Limit value is complied with starting from few metres in maximum radiation direction*
Mobile phone1920 MHz - 1980 MHzmax 1 W as peak value
DECT telephones-
Base station1880 MHz - 1900 MHz max 250 mW as peak value
Handset1880 MHz - 1900 MHzmax 250 mW as peak value
Wireless LAN and Bluetooth -

Wireless LAN

2400 MHz -
2484 MHz
max 100 mW
5100 MHz -
5800 MHz
max 1 W
Bluetooth 2400 MHz -
2480 MHz
max 100 mW
CB Radio Service-
Base station antenna

26.6 MHz -
27.4 MHz
a few watts28 V/m28 V/m, 0.73 A/m
Handheld 26.6 MHz -
27.4 MHz
max 4 W
Radar equipment-
Flight
surveillance (civil and military)
1 GHz - 10 GHz 0.2 kW - 2.5 MW 43.5 - 61 V/m or
5 - 10 W/m2, additional peak restrictions
43.5 - 61 V/m (corresponds to 5 - 10 W/m2), additional peak restrictions

Weather radar

1 GHz - 10 GHz

0.1 - 0.25 MW100 m in maximum radiation direction / 10 W/m243.5 - 61 V/m or 5 - 10 W/m2, additional peak restrictions43.5 - 61 V/m, 0.117 - 0.16 A/m (corresponds to 5 - 10 W/m2), additional peak restrictions
1 km in maximum radiation direction / 0.1 W/m2
Limit value is complied with in areas of public access

Traffic radar

9 GHz - 35 GHz Power
0.5 - 100 mW
3 m / 0.25 W/m261 V/m or 10 W/m2
10 m / < 0.01 W/m2
Limit value is complied with directly at the device
HF electronic article surveillance systems-

1 MHz - 10 GHz areas of public access / < 0.002 W/m228 - 87 V/m depending on the frequency

*) In directions other than the maximum radiation direction, the exposure usually falls below the limits after considerably smaller distances.
**) Typical transmitter powers as they are applied for with the Federal Network Agency in the site certification procedure.

Explanations for the limit values and the reference values

The "Ordinance on electromagnetic fields", based on the Federal Immission Control Act (26th BImSchV, see Limit values) applies to stationary high-frequency installations. The 26th BImSchV does not set any limits for transmitters with radiated powers EIRP of less than 100 mW, such as customary WLAN routers. The limit values of the 26th BImSchV apply to transmitters with more than 100 mW EIRP but less than 10 W EIRP, under certain conditions. The table indicates starting from which distance from the transmitter antenna in maximum radiation direction (safety distance) the limits are usually complied with.

Installations transmitting in the frequency range between 100 kHz and 10 MHz have to comply with the limits for the instantaneous effective field strengths and the limits for immission averaged over 6 minutes. Additional conditions apply to pulsed emissions (e.g. radar).

The 26th BImSchV does not apply to mobile high-frequency transmitters. Recommendations for limiting the Specific Absorption Rate (SAR) in accordance with the EU Council recommendation 1999/519/EC apply to mobile devices, such as mobile phones, that are used in close proximity to the human body. As the body is very close to the antenna and has a feedback effect on the transmitter, the energy absorbed by the body (the specific absorption rate) has to be limited. It is not sufficient to limit the electric or magnetic field strength.

State of 2018.03.14

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