The sensitivity to this topic has been stimulated by the intensive use of mobile phones and the presence of strong radio and television transmitters. It was realized that the EMF sources are many and, lately, it has become common knowledge that radio transmitters are not the only ones to emit potentially harmful fields to people.
The verification of compliance with the limits of human exposure is conducted today by applying different methods depending on the characteristics of the electromagnetic field source and its position with respect to persons. To be done properly, it requires skilled and experienced personnel in this field.
So there are specific assessment methods for equipment used near the ear, such as mobile phones, those used near the body including laptops, and those that are located on a table or on a wall or on the floor such as routers Wi-Fi and appliances.
In order to be marketed, all portable devices being used in the vicinity of the head or body must be subjected to tests SAR to demonstrate their compliance with these standards. The SAR is defined as the amount of EM energy absorbed by the human body per unit mass and is measured in W / Kg.