What does SAR measure?

SAR stands for Specific Absorption Rate. It is the standardized measurement of the rate at which radio frequency (RF) energy is absorbed by the tissue of the human body. This measurement is essential for establishing safety guidelines for RF exposure, particularly for devices that operate in very close proximity to the body, such as handheld amateur radio transceivers and mobile phones. Distractors such as "Signal attenuation ratio" or "Signal amplification rating" are plausible-sounding technical fabrications designed to test whether you know SAR is a biological exposure metric, not an electronics metric.