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Chapter
8
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8.10.2 Safety rules
8.10.2.1 Environmental protection
For an exterior installation, it is necessary to take precautions against lightning affecting the location of
the 4070 IO/EO.
8.10.2.1.1 Conditions for using lightning protection
Protection of 4070 IO/EO against lightning should be used when they:
•
Are less than 1.5 m from a wall more than 2 m below the antenna.
•
Use an external airborne connection between the base station and the system.
8.10.2.2 Recommendations for exposure of the public to the electromagnetic field
8.10.2.2.1 Magnetic absorption rate
Exposure of the public to the electromagnetic field from DECT sets and base stations is measured
using the Specific Absorption Rate (SAR) measuring unit. 2 W/kg is the SAR limit value indicated in
international recommendations and also in the European recommendation (1999/519/EC).
The DECT authorized SAR limit value is 2 W/kg on 10 g of body tissue (local SAR). International
recommendations include a safety margin for the public and take account of possible measuring
variations.
SAR values
•
Set: as the average power emitted from a set is lower than 20 mW, the set is considered to comply
without having to undergo any tests (see: EN 50371). The SAR value for DECT sets is not
significant.
•
Base station: the local SAR (head and chest) on 10 g of body tissue for DECT base stations (e.g.:
4070) is lower than 0.5 W/kg (this is with an integrated omni-directional antenna).
8.10.2.2.2 Antennae characteristics
8.10.2.2.2.1 Integrated antennae
The following is a list of characteristics for integrated antennae:
•
Bandwidth: 1.88 to 1.93 Ghz
•
Impedance: 50 Ohms
•
TOS: 1.5:1
•
Gain: 3 dBi (maximum)
•
Polarization: vertical (axis of the antenna)
•
Width of the beam at 3 dB (vertical): 90º
•
Radiation diagram: omni-directional in the horizontal plane.
8.10.2.2.2.2 External antennae
According to the ETSI EN 301 406 standard, DECT antenna gain is limited to 12 dB +/-3dB. In the case
of external directional antennae, if a minimum safety distance of 50 cm is respected, the SAR value is
the same as the value obtained in the case of an integrated omni-directional antenna (and therefore,
lower than: 0.5 W/kg).
8.10.2.2.3 Conformance perimeter for exposure of the public
•
Integrated omni-directional antennae: no limit for the conformance perimeter
•
External antenna (directional): the installation must allow for a safety perimeter respecting a
minimum distance of 50 cm.
8AL91217USAA - Ed. 01 - July 2018 - Installation Manual
Device commissioning
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