SAR Testing

Exposure excessive levels of radio frequency (RF) energy can damage human tissue. To minimize the potential for damaging exposure to RF Energy, many countries around the world have adopted standards that limit the amount of RF exposure allowed from transmitters of all types. BACL can determine if your product meets those requirements.

RF exposure from licensed radio devices or from certain classes of unlicensed wireless devices that are (or may be) used within 20 cm of the human body (i.e., from devices that are worn on or close to the body, or are hand-held) are subject to SAR requirements. The RF exposure from such devices is evaluated using one or more “phantoms” whose shapes and tissue simulant liquids simulate the electrical characteristics of the human head or body.

During SAR testing, the RF energy penetrating the applicable “phantom” is monitored by using a robotic system that precisely positions probes that measure the Specific Absorption Rate (SAR) of RF Energy emitted from the product in Watts per kilogram (or milliWatts per gram) of tissue.  Therefore, SAR, is a measure of the heating value of radiated RF energy on human tissue.

In the United States, the FCC regulates SAR under 47 CFR Part 2, Section 2.1093.  The equivalent SAR requirements for Canada are stated ISED Canada RSS-102.  Products intended for general use in the USA and Canada must meet a SAR limit of 1.6 mW/g averaged over one gram of tissue in any part of the head or body, and 4 mW/g averaged over 10 grams for hands, wrists, feet, and ankles.

In Europe (i.e., in the EU, EFTA, and EEA nations), the RF exposure limits are based upon the International Commission on Non-Ionizing Radiation Protection (ICNIRP) limits that are used in various Standards (e.g., EN 50360, EN 50566, etc.) that are harmonized under the 2014/53/EU Radio Equipment Directive [RED].  These Harmonized standards cover the most common products such as cell phones and RFID devices.  Products intended for general use must meet a SAR limit of 2.0 W/kg averaged over 10 grams of tissue in any part of the head or body, and 4 W/kg averaged over 10 grams for limbs.  Additionally, the “whole body” exposure is required to be limited to 0.08 W/kg.  The methods of RF exposure evaluation in the EU are similar but not identical to those in the US.

In order to assist our customers with compliance to regulations that limit RF exposure, BACL offers comprehensive Specific Absorption Rate (SAR) testing for unlicensed wireless and licensed radio devices.  BACL Sunnyvale’s ISO/IEC 17025