|
|
|
Electromagnetic Fields > Cordless phones with low EMF radiation levels
|
|
Cordless phones with low EMF radiation levels
|
|
With a low average transmitting power of less than 20 milliwatt (mW), DECT telephones comply with the current SAR limit of 2 watt per kilogram (W/kg). According to DIN EN 50360 and in contrast to mobile phones, it is therefore not necessary to establish the SAR value to demonstrate compliance with the limit or for manufacturers to display this value.
During operation in stand-by mode the base station of a DECT cordless phone continuously sends a control signal to the handset. During active use the phone’s transmitting power remains at a constant maximum regardless of the distance between the handset and the station.
Aiming at a precautionary reduction in exposure, the Federal Office for Radiation in 2006 issued the following criteria for cordless phones with low EMF radiation levels:
- automatic switch-off or a minimum 100,000-fold reduction of the control signal in stand-by mode - regardless of the number of handsets involved, eg., the handset does not need to be returned to the base station;
-
demand-driven graded regulation of handset transmitting power (more than 2 stages) when telephoning – similar to mobile phones;
- demand-driven graded regulation of base station transmitting power (more than 2 stages) when making a phone call;
- possibility of attaching a headset to the handset;
- possibility of setting / limiting the maximum distance.
In the meantime several manufacturers have applied, fully or partially, these criteria. Such low-radiation models usually make use of the own label of the manufacturer. Since such labels are not standardised and since device specifications may be subject to ongoing changes, consumers are recommended to check the technical specifications carefully against the above-mentioned criteria prior to purchase.
At the end of 2009 cordless digital telephones fulfilling the criteria specified in the award conditions concerning energy efficiency and low radiation also became eligible for “Blue Angel” environmental certification.
More information on the "Blue Angel" conditions for DECT phones can be found on the website of the RAL Deutsches Institut für Gütesicherung und Kennzeichnung e.V.. The environmental seal is only awarded if the manufacturer can prove compliance with the prescribed criteria upon examination. Consumers can therefore be sure that the phones satisfy the criteria in question.
|
|
Printer safe version
|
|
|
