Conformity With Standards - IFM Electronic efector 190 DTE820 Operating Instructions Manual

RFID UHF Sensor

8 Conformity with standards

Since the RFID systems are radio systems, they are in the scope of the 1999/5/EC
guideline of the European Commission (Radio and Telecommunications Terminal
Equipment R&TTE)�
As evidence of the conformity with the basic requirements of this guideline there is
a number of harmonised standards that are published in the Official Journal of the
European Union�
The ifm antennas have a passive antenna structure� The system integrator is
responsible for meeting the standards� Therefore it is expressly recommended to
acquire these standards�
Two important standards in connection with antennas are (not exhaustive)
EN 302208 and EN 50364: The first one deals with radio spectrum matters and
limits the maximally radiated power while
EN 50364 deals with the limitation of human exposure to electromagnetic fields�
As evidence of the antenna conformity with the standard EN 50364 the specific
absorption rate (SAR) is calculated numerically� The determined SAR values are
compared with the basic limit values of EN 50364 - classified to occupational
exposure, exposure of the general public and local exposure of head and
trunk and limbs� The WiRa is in general used for applications with a reading
area starting with 20 cm� At this distance the values are significantly below the
maximum SAR values permitted by law� In case that use is intended for smaller
distances, the respective SAR values are numerically calculated� The assumptions
taken as basis (such as operating mode of the RFID system and characteristics
of the human tissue) ensure a conservative estimate of the exposure (worst case
scenario)�
The calculation was also made for the most sensitive constellation
i�e� for the case that members of the general public stay permanently in direct
vicinity of the antenna with their head or trunk�
If the distance between the person and the antenna is less than 3 cm, the
DTE820 ensures that the maximally allowed SAR is not reached with an antenna
input power of up to 0�34 W (25�31 dBm)� In all other cases the DTE820 can be
operated with the maximally radiated power of 0�5 W ERP (27 dBm) or an antenna
input power of 0�653 W (28�15 dBm)� The table below shows the maximum
input powers with which the antenna may be supplied to ensure that the basic
limit values of the SAR are not exceeded� Two different types of exposure are
differentiated:
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