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.
Permittivity Verification
Meaning
Chemical assessment of the tissue-simulant fluid confirms its electrical properties align with standard human tissue characteristics. Executing permittivity verification before electromagnetic safety tests ensures that the absorption rate data is scientifically repeatable and valid. This metric measures the ability of the material to store electrical energy in an electric field.
Verification allows laboratories to claim that their simulated environment mimics an actual user during exposure evaluations.
Calibration Sequence
Sensors measure the dielectric constant of the liquid at the same frequencies the radio device will use. Permittivity verification looks for changes in the chemical balance of the fluid due to evaporation or contamination over time. If values drift by more than five percent, the lab must add specific salts or alcohols to rebalance the mixture.
Testing happens in a temperature-controlled environment to prevent thermal shifts in the material response.
Fluid Interaction
Signals penetrate deeper into fluids with low permittivity compared to high permittivity alternatives. Accuracy during permittivity verification directly impacts the SAR measurement because fluid behavior dictates the intensity of hotspots discovered by the probes. Using a consistent reference standard ensures that test results from different facilities around the globe are comparable.
Records of these fluid properties are updated daily in the quality logbook.
Phantom Setup
Before placing a device inside the phantom shell, technicians confirm permittivity verification is current for that session. This check confirms that the internal electromagnetic fields inside the test model develop as they would inside a human head or torso. Reports show both the target and measured values for permittivity across all active wireless bands.
If verification fails, all subsequent testing on the hardware is considered invalid.