The French agency that regulates radio frequencies, the ANFR, has notified Apple of its decision to ban iPhone 12 sales after tests showed the Specific Absorption Rate...
It’s not per kilogram of the device. It’s a measure of absorption per kilogram of body mass of the person using the device.
A good way to think about it is: throw a small piece of meat into the microwave and let it absorb some microwaves. It gets warm. Now imagine a much larger piece of meat. It can absorb a lot more microwaves before it starts getting warm. The smaller the ‘body mass’, the less radiation it can absorb and dissipate before becoming damaged. So when it comes to mobile device radiation levels, they focus on the watts of radiation absorbed per kilogram of body mass.
It’s not per kilogram of the device. It’s a measure of absorption per kilogram of body mass of the person using the device.
A good way to think about it is: throw a small piece of meat into the microwave and let it absorb some microwaves. It gets warm. Now imagine a much larger piece of meat. It can absorb a lot more microwaves before it starts getting warm. The smaller the ‘body mass’, the less radiation it can absorb and dissipate before becoming damaged. So when it comes to mobile device radiation levels, they focus on the watts of radiation absorbed per kilogram of body mass.