Testing >> Wireless/Radio Testing >> SAR - Specific Absorption Rate

Eurofins Product Testing - Specific Absorption Rate (SAR)

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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 body exposed 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.

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

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 …".

EN 50360:2001 Product standard to demonstrate the compliance of mobile phones with the basic restrictions related to human exposure to electromagnetic fields (300 MHz - 3 GHz)

EN 62209-1:2006

Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices - Human models, instrumentation, and procedures -- Part 1: Procedure to determine the specific absorption rate (SAR) for hand-held devices used in close proximity to the ear (frequency range of 300 MHz to 3 GHz)
EN 62311:2008 Assessment of electronic and electrical equipment related to human exposure restrictions for electromagnetic fields (0 Hz - 300 GHz)
EN 50364:2001 Limitation of human exposure to electromagnetic fields from devices operating in the frequency range 0 Hz to 10 GHz, used in Electronic Article Surveillance (EAS), Radio Frequency Identification (RFID) and similar applications
EN 50371:2002 Generic standard to demonstrate the compliance of low power electronic and electrical apparatus with the basic restriction related to human exposure to electromagnetic field (10 MHz - 300 GHz) - General Public
EN 50385:2002 Product standard to demonstrate the compliance of radio base stations and fixed terminal stations for wireless telecommunication systems with the basic restrictions or the reference levels related to human exposure to radio frequency electromagnetic fields (110 MHz - 40 GHz) - Occupational
EN 50385:2002 Product standard to demonstrate the compliance of radio base stations and fixed terminal stations for wireless telecommunication systems with the basic restrictions or the reference levels related to human exposure to radio frequency electromagnetic fields (110 MHz - 40 GHz) - General public

FCC-USA:

47CFR 2.1091 and 2.1093

FCC OET Bulletin 65, Supplement C (portable transmitting devices)

IEEE 1528:200X Recommended Practice for determining the peak Spatial - Average Absorption Rate (SAR) in the Human Body Due to Wireless Communications Devices: Experimental Techniques

IC-Canada:

Health Canada's Safety Code 6

RSS-102 Issue 2 Radio Frequency Exposure Compliance of Radio communication Apparatus (All Frequency Bands)

Australia:

Radio communications (Electromagnetic Radiation - Human Exposure) Standard 2003

RPS No. 3 Radiation Protection Standard
Maximum Exposure Levels to Radio frequency Fields - 3 kHz to 300 GHz

International:

IEC 62209 Human exposure to radio frequency fields from hand-held and    body-mounted wireless communication devices - Human models, instrumentation, and procedure

 

Contact our wireless radio and mobile communication expert today!

via phone: +49 33631 888 0

or via eMail: wireless@eurofins.com
or contact our national organisation in your country.