Head case

The IEEE has approved a new recommended practice, IEEE 1528, for assessing radio-frequency energy delivered to the heads of users of cellular phones and other personal communication devices.

The Institute of Electrical and Electronics Engineers (IEEE) has approved a new recommended practice, IEEE 1528, for assessing radio-frequency energy delivered to the heads of users of cellular phones and other personal communication devices.

It is based on a model of the human head filled with a fluid having the microwave electrical properties similar to a composite head tissue.

IEEE 1528, ‘Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Head from Wireless Communications Devices: Measurement Techniques,’ specifies experimental protocols and measurement and validation methods for hand-held wireless transceivers operating between 300 MHz and 3 GHz.

The new standard will help wireless device manufacturers and regulators assess compliance with the requirements of the US Federal Communications Commission (FCC) and similar government agencies in other countries – that limit RF exposure from personal communication devices.

Measurements under the standard are made using an electric field probe that scans the tissue-equivalent liquid inside the model head and measures maximum SAR in volumes of one or ten grams. The model is intended to give a conservative estimate of the maximum peak spatial-average SAR that can be expected to occur anywhere in the heads of most people when they use hand-held communication devices held against their ear.

IEEE 1528 was sponsored by the IEEE Standards Co-ordinating Committee 34 for Electromagnetic Energy Product Performance Safety. It was developed with a number of members who also have common membership in the International Electrotechnical Commission’s Technical Committee 106 to ensure harmony with the IEC’s efforts.

The IEEE standard does not set specific limits for exposures of users of cellular phones and other personal communication devices, but it may be used for assessing compliance with limits found in a number of contemporary standards and guidelines. These limits are set by the FCC in the US and are based in part on IEEE C95.1-1991, ‘Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz.’ Government agencies in other countries have adopted similar limits.