Meaning
Electromagnetic exposure exemption criteria for low-power wireless devices determine whether a transmitter must undergo physical absorption testing. Standardized bluetooth le sar exclusion methods bypass the expensive laboratory evaluation when the radiated power falls below a calculated threshold. This exemption relies on a combination of output power and separation distance to the user.
Power Threshold
Transmitter output power is compared directly against the limits defined by regulatory bodies. When the peak envelope power is less than the exclusion limit, the device is exempted from testing. This threshold varies depending on the operational frequency of the radio module.
Distance Calculation
Separation distance between the antenna structure and the human body must be established from the mechanical housing drawing. A default distance of five millimeters is applied when the actual separation is smaller. This value is used in the mathematical formula to find the exemption threshold.
Exemption Verification
Technical documentation confirms the compliance status by presenting the calculated limits alongside the laboratory-measured output power. This technical documentation forms part of the final radio equipment filing. When the exclusion is verified, the manufacturer does not need to schedule a dynamic absorption test with a liquid phantom, which accelerates the release schedule.
This process is validated during the module integration phase to ensure that no modifications to the housing or the antenna placement have invalidated the initial calculation.
