Meaning
Exposure verification protocols determine the rate at which human tissue absorbs radio-frequency energy from wireless devices. This dosimetric assessment occurs during the regulatory certification of any handheld or body-worn transmitter. Automated probes measure the electric field strength inside a liquid-filled phantom that replicates the electrical properties of human muscle, providing a baseline of radio safety.
Measurement Protocol
Specific anthropomorphic phantoms hold the device under test in standardized positions next to the simulated head or body. The test starts by scanning the probe over a broad grid to locate the region of highest energy absorption. A localized three-dimensional scan then calculates the peak spatial-average absorption rate, which must remain within statutory guidelines.
Dielectric Liquid
Simulating the behavior of human tissue requires a carefully calibrated mixture of water and organic solvents. The dielectric constant of this liquid must match the values specified by regulatory bodies like the Federal Communications Commission. Daily calibrations prevent evaporation from altering the fluid properties.
Compliance Threshold
Regulatory limits dictate the maximum permissible exposure to prevent localized thermal damage. Handheld transmitters must operate below two watts per kilogram averaged over ten grams of tissue. Passing this evaluation allows the product to enter the commercial market.
