What does Specific Absorption Rate (SAR) measure?

The Specific Absorption Rate (SAR) measures the amount of radio frequency (RF) energy absorbed by biological tissue. It is expressed in watts per kilogram (W/kg) and is particularly significant in assessing the safety of devices that emit RF energy, such as mobile phones and other wireless devices. Regulatory agencies use SAR values to set limits on exposure to ensure that electronic devices do not exceed safe thresholds for human interaction, protecting users from potential harmful effects associated with high levels of RF exposure.

Understanding SAR is crucial for evaluating how effectively and safely devices transmit RF energy, especially in terms of potential thermal impacts on human tissue. While SAR does relate to thermal effects, it is specifically focused on the absorption of RF energy rather than just thermal outcomes. The context of exposure to RF energy is immensely relevant in various fields, especially in medical and occupational health, as it helps to formulate guidelines and standards for safe device operation.