Overview
IEC TS 62997:2017 provides guidance for evaluating hazards from magnetic nearfields in industrial electroheating (EH) and electromagnetic processing of materials (EPM). The technical specification covers the frequency range 1 Hz to 6 MHz and specifies how to characterise external magnetic nearfields, compute induced electric fields in body tissues, and assess specific absorption rates (SAR) including time integration. It is intended to manage induced electric shock phenomena and tissue overheating risks associated with industrial electromagnetic equipment.
Key topics and technical requirements
- Scope and definitions: Terminology, quantities and units for magnetic nearfield assessment (1 Hz–6 MHz).
- Basic relationships: Formulas and principles to determine in situ induced electric field strengths and coupling factors.
- Immediate nerve and muscle reaction controls:
- Methods such as Conductor Geometry and Current Restriction (CGCR).
- Volunteer test methods (several variants including similarity-based and elevated-current approaches).
- Use of magnetic nearfield reference levels (RLs) where applicable.
- Tissue overheating and SAR: Requirements for time-integrated SAR assessments (e.g., 6-minute integration and shorter times for fingers/hands).
- Numerical computations: Guidance on FDTD/FEM modelling, handling inaccuracies, uncertainties and applying safety factors.
- Verification approaches: When simple B-field measurements are sufficient versus when modelling or volunteer tests are required.
- Risk classification and marking: Risk groups, warning labels and practical examples of marking for equipment.
- Supporting annexes: Analytical calculations, reference bodypart models and dielectric properties, FDTD modelling case studies (Helmholtz coils, straight conductors), and frequency upscaling considerations.
Practical applications and users
IEC TS 62997:2017 is practical for:
- Manufacturers and designers of industrial electroheating and electromagnetic processing equipment who need to design for electromagnetic safety.
- Test laboratories and compliance engineers performing B-field, induced E-field and SAR assessments.
- Occupational health & safety specialists and plant engineers implementing risk controls, warning markings and safe operating procedures.
- Regulatory bodies and certifiers referencing standardised approaches for evaluating magnetic nearfield hazards.
- Modelling specialists applying FDTD/FEM numerical methods to predict in situ fields and validate mitigation measures.
Related standards
- References and comparisons are made to international exposure guidelines such as ICNIRP, IEEE standards and the EU 2013/35/EU framework (see Annex A for a survey of basic restrictions and reference levels).
Keywords: IEC TS 62997:2017, magnetic nearfields, electroheating safety, electromagnetic processing, induced electric field, SAR, CGCR method, volunteer test, FDTD modelling, industrial electromagnetic equipment.