Eurofins Product Testing - Specific Absorption Rate (SAR)
| SAR is the rate of RF (Radio Frequency) energy absorption per unit mass in the body. SAR has units of joules per second per kilogram or watts per kilogram (W/kg). | ||||||||||||||||||||||||
| This parameter is used as a primary indicator of RF - energy absorbed in the body when quantifying the biological effects and thus defining the basic exposure limits. At frequencies between 100 kHz and 10 GHz, SAR limits take precedence over field strength and power density limits and shall not be exceeded. When carrying out compliance evaluation, the SAR should be determined for cases where exposures take place at a distance of 20 cm or less from the source. The SAR in a biological bodyexposed to a RF field depends on a number of factors including tissue geometry and dielectric properties and the orientation of the object relative to the source. Since the RF energy induced in the body is scattered and absorbed at various interfaces, the internal field and hence the SAR distribution is non - uniform. | |
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The SAR measurements are carried out by scanning the tissue medium along the interior of a phantom with a robotically- controlled miniature E-field probe. Once the region of highest SAR is identified, algorithms are used to average over the prescribed volume to determine the peak spatial average. Different shaped phantoms and tissue mediums simulate the exposed part of the body for head and body worn equipment. Eurofins uses the professional SAR measurements system DASY 4 (from the Swiss supplier Schmid and Partner) for SAR evaluation. This fully automatic measurement system is approved by all national certification authorities. Features of DASY 4 are: 3-dimensional readouts with coloured zone indication, automatic calibration routines, peak detection and peak spatial-average SAR evaluation are detailed monitored and reported in the test documentation. Different phantoms and tissue mediums enable our lab to SAR tests for radio base stations, fixed terminal stations for wireless communication systems and related antennas according to all major RF exposure standards. Furthermore general RF exposure routines can be evaluated by our experts and reported with a “RF - Exposure Consideration Document”. |
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l: DASY4 readout simulation in phantom's head r: Zone - simulation of an Radio module |
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SAR testing is required primarily for: cellular phones, PDA (Personal Digital Assistant), headsets, laptops, PC-card..... Regional SAR Requirements:European Union:R&TTE directive article 3.1a, “…the protection of the health and the safety of the user and any other person …”.
FCC-USA:47CFR 2.1091 and 2.1093 FCC OET Bulletin 65, Supplement C (protable transmitting devices)
IC-Canada:Health Canada’s Safety Code 6
Australia:Radio communications (Electromagnetic Radiation - Human Exposure) Standard 2003
International:
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| For further information please contact our national organisations or our specialists or get in touch directly with our wireless radio and mobile communication experts: Phone: +49 (0) 33631 888-0 eMail: wireless@eurofins.com |

