Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to 100 kHz with regard to exposure of human beings - Part 2: Basic standard for measurements
Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to 100 kHz with regard to exposure of human beings - Part 2: Basic standard for measurements
IEC 61786-2:2014 provides requirements for the measurement of quasi-static magnetic and electric fields that have a frequency content in the range 1 Hz to 100 kHz, and DC magnetic fields, to evaluate the exposure levels of the human body to these fields. Specifically, this standard gives requirements for establishing measurement procedures that achieve defined goals pertaining to human exposure. Because of differences in the characteristics of the fields from sources in the various environments, e.g. frequency content, temporal and spatial variations, polarization, and magnitude, and differences in the goals of the measurements, the specific measurement procedures will be different in the various environments. Sources of fields include devices that operate at power frequencies and produce power frequency and power-frequency harmonic fields, as well as devices that produce fields independent of the power frequency, and DC power transmission, and the geomagnetic field. The magnitude ranges covered by this standard are 0,1 micro-Tesla to 200 mili-Tesla for AC (1 micro-Tesla to 10 Tesla for DC) for magnetic fields, and 1 V/m to 50 kV/m for electric fields. When measurements outside this range are performed, most of the provisions of this standard will still apply, but special attention should be paid to the specified uncertainty and calibration procedures. Examples of sources of fields that can be measured with this standard include: - devices that operate at power frequencies (50/60 Hz) and produce power frequency and power-frequency harmonic fields (examples: power lines, electric appliances...); - devices that produce fields that are independent of the power frequency.(Examples: electric railway (DC to 20 kHz); - commercial aeroplanes (400 Hz), induction heaters (up to 100 kHz), and electric vehicles); - and devices that produces static magnetic fields: MRI, DC power lines, DC welding, electrolysis, magnets, electric furnaces, etc. DC currents are often generated by converters, which also create AC components (power frequency harmonics), which should be assessed. When EMF products standards are available, these products standards should be used. With regard to electric field measurements, this standard considers only the measurement of the unperturbed electric field strength at a point in space (i.e. the electric field prior to the introduction of the field meter and operator) or on conducting surfaces. Sources of uncertainty during measurements are also identified and guidance is provided on how they should be combined to determine total measurement uncertainty.
IEC 61786-2:2014 is an international standard developed by the International Electrotechnical Commission (IEC) that establishes fundamental requirements for the measurement of DC magnetic, AC magnetic, and AC electric fields in the frequency range from 1 Hz to 100 kHz. This standard is specifically designed to assess human exposure to quasi-static magnetic and electric fields, providing a basis for accurate and consistent measurement procedures across various environments. It addresses a critical need for reliable data to evaluate compliance with human safety and health regulations concerning electromagnetic fields (EMF).
The standard covers magnetic fields from 0.1 µT to 200 mT for AC and up to 10 T for DC, as well as electric fields from 1 V/m to 50 kV/m. It also highlights measurement challenges relating to field variability in frequency, temporal/spatial patterns, polarization, and magnitude, guiding users on adapting measurement techniques accordingly.
Measurement Scope and Frequency Range IEC 61786-2:2014 encompasses DC magnetic fields and AC magnetic/electric fields from 1 Hz to 100 kHz. This frequency range includes power frequency fields (50/60 Hz), harmonic components, and devices operating at frequencies independent of power systems.
Field Sources and Characteristics The standard addresses varied sources of electromagnetic fields including:
Measurement Methodology The document defines procedures for measuring unperturbed electric fields at specific points in space and on conducting surfaces, emphasizing minimizing interference by operators or instruments. It accounts for diverse field characteristics including temporal and spatial variation and multiple frequency components.
Uncertainty Analysis Important considerations are provided on assessing and combining sources of measurement uncertainty, involving instrument calibration, environmental effects (temperature, humidity), field non-uniformity, and observer proximity effects. This ensures reliability and repeatability of exposure assessments.
Стандарты, упомянутые в описании
Measurement Reporting IEC 61786-2 outlines essential details to include in measurement reports, facilitating traceability, comparability, and regulatory compliance.
Human Exposure Assessment This standard is essential for evaluating human exposure levels to magnetic and electric fields in residential, occupational, and public environments as part of health and safety programs.
Regulatory Compliance Organizations responsible for ensuring safety around electromagnetic field sources use this standard to verify compliance with international and regional exposure limits.
Electromagnetic Compatibility (EMC) Testing IEC 61786-2 supports product evaluation and EMF emissions testing for devices operating within its frequency and field strength ranges.
Research and Development Researchers analyzing the impact of electromagnetic fields on biological systems and environments benefit from standardized measurement protocols.
Industrial and Infrastructure Monitoring Utilities, transport system operators, and medical facilities adopt these measurement techniques to monitor field levels from power transmission, electric trains, MRI facilities, and welding operations.
These related standards complement IEC 61786-2 by addressing product-specific emissions, exposure evaluation, and additional measurement environments, forming a comprehensive framework for EMF measurement and assessment.
Keywords: IEC 61786-2, DC magnetic field measurement, AC magnetic field measurement, AC electric field measurement, electromagnetic field exposure, human safety, measurement uncertainty, power frequency EMF, quasi-static fields, electromagnetic compatibility, EMF human exposure standards, magnetic field measurement procedures, electric field measurement methods.