What is SAR, SAR Testing Requirements.

Specific Absorption Rate (SAR) is the unit of measurement for the amount of radio frequency (RF) absorbed by the body when using a wireless device. The SAR value is expressed in terms of watts per kilogram (W/kg) or milliwatts per gram (mW/g). The RF exposure limits used are expressed in the terms of SAR, which is a measure of the electric and magnetic field strength and power density for transmitters operating at frequencies from 300 kHz to 100 GHz. The FCC and other federal governmental agencies around the world require that any wireless device be evaluated to meet the RF exposure limits set forth in the governmental SAR regulations.

The most generally accepted method for measuring SAR values is the direct method SAR test. This method utilizes a model called a “SAM phantom” to simulate the human head and a “flat phantom” to simulate the human body. With this method, wireless devices are tested at the highest certified power level in laboratory conditions utilizing a SAR test system with a robot. An orthogonal probe is mounted on the robot arm to measure the RF fields transmitted into a calibrated tissue simulant. 

Worldwide Standards

The SAR testing requirement is being added to many countries around the world. Numerous other countries are in the process of evaluating the need to add SAR testing to their requirement. The following is a list of the standards for SAR testing at present.

FCC OET Bulletin 65 Supp. C

Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields – Additional Information for Evaluating Compliance of Mobile and Portable Devices with FCC Limits for Human Exposure to Radiofrequency Emissions.

IEEE 1528 Std.- 2003

Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Head from Wireless Communications Devices: Measurement Techniques

Industry Canada – RSS – 102

Evaluation Procedure for Mobile and Portable Radio Transmitters with respect to Health Canada's Safety Code 6 for Exposure of Humans to Radio Frequency Fields

Industry Canada – Health Safety Code 6

Limits of Human Exposure to Radiofrequency Electromagnetic Fields in the Frequency Range from 3 kHz to 300 GHz

Australian Communication Authority

Radiocommunications (Electromagnetic Radiation – Human Exposure) Standard 2003

Australian Communication Authority

Radiocommunications (Compliance Labelling - Electromagnetic Radiation) Notice 2003

Australian Communication Authority

Radiation Protection Series No. 3 – Maximum Exposure Levels to Radiofrequency Fields – 3kHz to 300 GHz

International Electrotechnical Commission (IEC) – IEC 62209

Procedure to determine the Specific Absorption Rate (SAR) for hand-held mobile telephones in the frequency range of 300 MHz to 3GHz

European Union – EN 50360

Product Standard to Demonstrate the Compliance of Mobile Phones with the Basic Restrictions Related to Human Exposure to Electromagnetic Fields (300 MHz – 3 GHz)

European Union – EN 50361

Basic Standard for the Measurement of Specific Absorption Rate Related to Exposure to Electromagnetic Fields from Mobile Phones (300 MHz – 3 GHz)

European Union – EN 50364

Limitation of Human Exposure to Electromagnetic Fields from devices operating in the Frequency Range of 0 Hz to 10 GHz, used in Electronic Article Surveillance (EAS), Radio Frequency Identification (RFID) and similar applications

European Union – EN 50371

Generic Standard to Demonstrate the Compliance of Low Power Electronic and Electrical Apparatus with the Basic Restrictions related to Human Exposure to Electromagnetic Fields (10 MHz – 300 GHz) – General Public