Overview
IEC TR 62630:2010 - Guidance for evaluating exposure from multiple electromagnetic sources provides practical, consensus-based guidance for assessing combined human exposure to multiple narrowband electromagnetic (EM) sources in the 100 kHz to 300 GHz frequency range. The report focuses on energy-based exposure metrics - specific absorption rate (SAR) and equivalent power density (S) - and addresses how to estimate overall exposure when several intentional transmitters operate simultaneously under static conditions (source positions and transmit characteristics do not vary significantly during measurement).
Key topics and technical scope
- Frequency and signal scope: Narrowband sources (fractional bandwidth ≤ 10% of centre frequency) in 100 kHz–300 GHz. Wideband/UWB systems are noted but not the primary focus.
- Exposure metrics: Guidance specifically targets SAR (internal/tissue heating) and equivalent power density (external fields).
- Summation techniques: Explains approaches for combining fields from multiple sources, including:
- Summation of internal fields for SAR and of external fields for power density.
- Methods for uncorrelated vs correlated sources (e.g., independent transmitters vs beam-steering/adaptive arrays).
- Vector-sum (accurate) versus conservative scalar-sum approaches and implications when using scalar sensors.
- Device and source classification: Differentiates user-centric vs node-centric devices, single-channel vs band-wide transmitters, and provides practical source classes.
- Measurement considerations: Guidance on selecting appropriate evaluation techniques (field measurements, analytical estimates) and on interpreting results under the assumption of static test conditions.
- Informative annexes: Frequency allocations for common services, analytical support, and worked examples illustrating combined-exposure evaluations.
Practical applications
- Evaluating combined RF exposure around:
- Multi-band wireless handsets (multiple antennas on the same device)
- Shared/base-station sites and multi-sector cellular masts
- Smart antenna arrays and beam-forming systems
- Informing product design and site deployment decisions to manage aggregate exposure
- Supporting test-plan development and exposure assessments used by safety, compliance, and engineering teams
Who should use this technical report
- IEC TC 106 project teams developing exposure standards
- RF and compliance engineers performing exposure assessments (SAR and power-density)
- Health & safety and regulatory specialists assessing aggregate exposure from multiple transmitters
- Test laboratories and certification bodies seeking guidance on summation approaches
Related standards and guidance
- References IEC 62209-1 (human exposure from handheld and body‑mounted wireless devices) and aligns with the main international exposure guidelines that set SAR and power-density limits. IEC TR 62630 does not itself define compliance test methods or regulatory limits - those are covered in product compliance standards and national regulations.
Keywords: IEC TR 62630:2010, electromagnetic exposure, combined exposure, SAR, power density, multiple sources, narrowband, RF safety, IEC TC 106.