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IEC 10026-2-00:2004 – Radiated Emission Measurement Methods for EMC Compliance: Scope, Technical Requirements, and Compliance Notes
A comprehensive guide to understanding the requirements of IEC 10026-2-00 for electromagnetic compatibility testing of electrical and electronic equipment.
IEC 10026-2-00:2004, part of the IEC 10026 series on electromagnetic compatibility (EMC), specifies standardized methods for measuring radiated emissions from electrical and electronic equipment. It is essential for manufacturers, test laboratories, and compliance engineers seeking to ensure products meet international emission limits. This article provides an in-depth analysis of the standard’s scope, technical requirements, implementation considerations, and compliance notes.
1. Scope of IEC 10026-2-00:2004
IEC 10026-2-00:2004 defines the measurement procedures and instrumentation requirements for radiated emission testing in the frequency range from 30 MHz to 1 GHz. The standard applies to both Class A (industrial) and Class B (residential/commercial/light industrial) equipment. It covers test site validation, antenna selection, and measurement distances (typically 3 m, 10 m, or 30 m). The primary objective is to ensure reproducible and comparable emission measurements across different laboratories worldwide.
The standard is applicable to all electrical and electronic apparatus that may generate electromagnetic disturbances, including information technology equipment, household appliances, and industrial machinery. It forms the basis for many product-specific emission standards and is widely referenced by regulatory bodies such as the FCC (USA) and ETSI (Europe).
2. Technical Requirements for Radiated Emission Measurements
2.1 Measurement Setup
The test setup must follow a prescribed geometry: the equipment under test (EUT) is placed on a non-conductive table (0.8 m height for tabletop equipment) or on a turntable inside a semi-anechoic chamber (SAC) or at an open-area test site (OATS). The measuring antenna is positioned at specified distances and heights to capture both vertically and horizontally polarized emissions. For peak, quasi-peak, and average detection, the receiver must meet the characteristics defined in IEC 10026-1-00.
2.2 Antenna Requirements
Biconical and log-periodic antennas are commonly used for the frequency range covered. Antenna factors must be calibrated at least annually using a recognized traceable method. The standard requires that the antenna be scanned from 1 m to 4 m height for maximum emission capture at each frequency and polarization.
2.3 Test Site Validation
Before performing compliance measurements, the test site must be validated using the normalized site attenuation (NSA) method. The measured NSA shall be within ±4 dB of the theoretical value over the entire frequency range. This ensures that site reflections or absorber performance do not distort results.
2.4 Emission Limits
| Frequency Range (MHz) | Class A – Quasi-Peak @ 10 m (dBµV/m) | Class B – Quasi-Peak @ 10 m (dBµV/m) |
|---|---|---|
| 30 – 88 | 40 | 30 |
| 88 – 216 | 47 | 33.5 |
| 216 – 230 | 50 | 36 |
| 230 – 1000 | 57 | 36 |
For measurements at 3 m, add 10 dB to the 10 m limits. Where average detection is used, the limits are usually 10 dB lower than quasi-peak values (subject to product standards).
Tip: For measurements above 1 GHz, refer to IEC 10026-2-01, which extends the frequency range to 6 GHz and introduces horn antennas and free-field conditions.
Warning: Always ensure the test site meets NSA requirements before conducting final compliance tests. Failure to validate can invalidate the entire measurement campaign.
3. Implementation Highlights for Test Laboratories
3.1 Calibration and Measurement Uncertainty
Radiated emission measurements require careful control of uncertainty. IEC 10026-2-00 mandates that the combined measurement uncertainty be calculated according to the methods in IEC 10026-1-00 and must not exceed 5.2 dB (with a coverage factor k=2). Regular inter-laboratory comparisons are recommended to verify consistency.
3.2 Prescan and Final Measurement
The standard recommends a two-step process: a prescan using peak detection at a fast sweep to identify critical frequencies, followed by a final measurement with quasi-peak or average detection at those frequencies. For Class B equipment, a lower limit applies, so the test receiver’s noise floor should be at least 6 dB below the limit.
3.3 EUT Configuration and Operation
The EUT must be operated in a representative mode that maximizes emissions. Cables should be arranged in a typical manner, and any ancillary equipment should be included unless it is exempted. The standard provides detailed guidance on tabletop versus floor-standing setups and handling of peripherals.
Success: Laboratories that implement periodic site verification and maintain meticulous calibration records significantly improve their pass rates during audits and proficiency tests.
4. Compliance Notes and Documentation
To demonstrate compliance with IEC 10026-2-00, the test report must include the following elements:
- Identification of the EUT, its operating mode, and any auxiliary equipment.
- Description of the test site (OATS, SAC, or FAR) with validation dates and NSA data.
- List of measurement equipment (antennas, receivers, cables) with calibration certificates.
- Plots or tables of measured emissions at each frequency, clearly showing the applicable limits.
- Statement of measurement uncertainty and a declaration of conformity (Pass/Fail) with acceptance criteria.
Manufacturers must also provide documentation showing that the product’s emissions do not change under normal variations of supply voltage, temperature, and humidity. Typical compliance requires that all emissions remain below the limit line by at least the measurement uncertainty margin.
Danger: Non-compliance with the test methods defined in IEC 10026-2-00 can lead to rejected test reports, product recalls, or market access barriers. Always follow the current edition of the standard.
Frequently Asked Questions
Q: What is the difference between IEC 10026-2-00 and IEC 10026-2-01?
A: IEC 10026-2-00 covers radiated emission measurements from 30 MHz to 1 GHz, while IEC 10026-2-01 extends the frequency range up to 6 GHz for higher-frequency disturbances. The measurement site and antenna requirements differ accordingly.
A: IEC 10026-2-00 covers radiated emission measurements from 30 MHz to 1 GHz, while IEC 10026-2-01 extends the frequency range up to 6 GHz for higher-frequency disturbances. The measurement site and antenna requirements differ accordingly.
Q: Can I use a fully anechoic room (FAR) instead of an open-area test site?
A: Yes, IEC 10026-2-00 allows the use of a FAR if it meets the site attenuation requirements. However, the standard requires that the measurement distance be corrected for the presence of absorbing material and that the site be validated with a reference radiator.
A: Yes, IEC 10026-2-00 allows the use of a FAR if it meets the site attenuation requirements. However, the standard requires that the measurement distance be corrected for the presence of absorbing material and that the site be validated with a reference radiator.
Q: Are the limits in the table mandatory for all product categories?
A: The limits are generic. Product-specific standards (e.g., IEC 55032 for multimedia equipment) may modify the levels or add additional frequency bands. Always apply the relevant product standard as primary reference.
A: The limits are generic. Product-specific standards (e.g., IEC 55032 for multimedia equipment) may modify the levels or add additional frequency bands. Always apply the relevant product standard as primary reference.
© 2026 – International Electrotechnical Commission. This article is for informational purposes and does not replace the official text of the standard.