EMI/EMC Standards CISPR11

The primary reference is CISPR 11:2024 (Edition 7.0), titled "Industrial, scientific and medical equipment – Radio-frequency disturbance characteristics – Limits and methods of measurement." For manufacturers targeting specific markets, it aligns with EN 55011 (European Union) and forms the emissions foundation for IEC 60601-1-2 (Medical Electrical Equipment) and IEC 61326-1 (Laboratory Equipment).

The scope is vast, covering any non-telecom device that generates RF energy for internal or external work:

• Industrial: Arc welders, induction heating systems, industrial robots, and plasma cutters.
• Medical: MRI scanners, X-ray machines, diathermy equipment, and ultrasound systems.
• Scientific: Mass spectrometers, signal generators, and laboratory-grade centrifuges.
• Domestic: Commercial microwave ovens and high-frequency induction hobs.

Testing is divided into two primary vectors to ensure a 360-degree EMI profile:

• Conducted Emissions: Measures RF noise injected into power lines (9 kHz to 30 MHz) using a LISN.
• Radiated Emissions: Evaluates field strength broadcasts through the air (up to 18 GHz depending on the group).
• Functional Loads: Testing is performed at full and half-power to capture worst-case interference scenarios.
• Wired Network Ports: Analysis of disturbances on data and communication cables.

To ensure global report acceptance, testing must be conducted at an ISO/IEC 17025 accredited laboratory. In the Indian context, labs should hold NABL (National Accreditation Board for Testing and Calibration Laboratories) credentials. For medical devices, the lab must be recognized by the CDSCO or relevant regulatory bodies to ensure the test report is valid for legal market entry.

A standard CISPR 11 evaluation typically spans 2 to 3 weeks.

• Week 1: Initial setup, pre-compliance "quick scans," and engineering modifications if failures occur.
• Week 2: Formal data collection across all frequency bands and operating modes.
• Post-Testing: Final report generation and QA review usually take an additional 3-5 business days.

For a robust evaluation, we typically require one fully functional production unit.

• Essential Accessories: All peripheral cables, software controllers, and auxiliary power supplies.
• Operation Manual: Detailed instructions on how to cycle the machine through its maximum RF-emitting modes.
• Spares: Critical fuses or proprietary connectors to prevent delays during intensive testing.

The investment for CISPR 11 testing varies based on the "Group" and "Class" of the product. Industrial Group 2 equipment (like welders) often requires more complex setups than Group 1. On average, a complete test suite ranges from ₹60,000 to ₹1,50,000, excluding any "on-site" (in-situ) testing fees for large-scale machinery that cannot be moved to a lab.

A successful filing requires a comprehensive technical dossier:

• Circuit Schematics & PCB Layouts: To trace EMI sources.
• Block Diagrams: Detailing internal RF oscillators and clock frequencies.
• Bill of Materials (BOM): Highlighting EMI filters and shielded components.
• User Manual & Labeling: Including necessary Class A/Class B warning statements for the end-user.