Editing Specific absorption rate (section)

{{Short description|Measure of absorption of energy by humans}}
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'''Specific absorption rate''' ('''SAR''') is a measure of the rate at which [[energy]] is [[Absorption (electromagnetic radiation)|absorbed]] per unit mass by a human body when exposed to a [[radio frequency]] (RF) [[electromagnetic field]]. It is defined as the [[Power (physics)|power]] absorbed per [[mass]] of [[body tissue|tissue]] and has units of [[watt]]s per [[kilogram]] (W/kg).<ref>{{cite book | first= Jianming |last= Jin | title= Electromagnetic Analysis and Design in Magnetic Resonance Imaging | year= 1998 | publisher= CRC Press | isbn= 978-0-8493-9693-9 | pages = §5.3.3 pp. 226ff }}</ref>

SAR is usually averaged either over the whole body, or over a small sample volume (typically 1&nbsp;g or 10&nbsp;g of tissue). The value cited is then the maximum level measured in the body part studied over the stated volume or mass.