Multijurisdictional Co Location SAR Evaluation Limits for Portable Host Devices
Multijurisdictional co-location SAR evaluation requires host-level total exposure ratio analysis and spatial decoupling to ensure global market clearance.
Human Body Separation
Meaning
Physical distance between a radiating component and a person determines the maximum allowable power level to minimize electromagnetic absorption. This human body separation metric classifies whether a device is treated as mobile, requiring at least twenty centimeters of clearance, or portable, operating in direct contact. Engineers measure this specific gap during the placement of antennas inside tablets, laptops or wearable technologies.
It serves as the primary factor in deciding which exposure testing methodologies apply.
Proximity Threshold
Devices designed for hand usage must pass much stricter absorption tests because the human body separation is nearly zero millimeters. For products used on desks, higher wattage is permitted because typical human body separation stays above fifteen centimeters. Sensor systems detect when an obstacle moves within the safe range and notify the firmware to adjust.
These measurements ensure local tissues are not exposed to high power densities over long durations.
Integration Profile
Changing the enclosure thickness alters the observed human body separation and potentially invalidates previous regulatory filings. Plastic bumpers and air gaps inside the chassis serve as mechanical buffers that maintain this distance. If the distance decreases, the radio must be limited through hard-coded software locks to maintain global safety standards.
The placement of the transceiver deep inside the unit increases this gap without making the exterior larger.
Safety Verification
Certification laboratories use robotic probes inside liquid-filled containers to measure fields at specific human body separation points. These tests prove that the electromagnetic interaction remains below standard SAR thresholds for the general population. If testing reveals a hotspot, designers move the radiator to increase human body separation.
The verified distance appears in the user manual as a required safety instruction for the installer.