CISPR 11

CISPR 11 specifies electromagnetic disturbance requirements for industrial, scientific and medical (ISM) equipment. It covers conducted and radiated RF emissions and provides the measurement methods and limits used to evaluate equipment within its scope.

The standard classifies equipment as Group 1 or Group 2 according to how RF energy is generated or used, and as Class A or Class B according to the intended electromagnetic environment.

CISPR 11 is also referenced by other EMC standards, including IEC 61326-1 for measurement, control and laboratory equipment and IEC 60601-1-2 for medical electrical equipment and systems.

The Standard applies to ISM equipment such as laboratory and measurement equipment, medical equipment, industrial machines and robots, induction and microwave heating equipment, RF welding equipment, and certain wireless power transfer systems.

Equipment covered by another CISPR product or product-family emission standard is excluded from the scope of CISPR 11.

International: CISPR 11 is an international EMC standard for industrial, scientific and medical equipment.

European Union: CISPR 11 is adopted in Europe as EN 55011 and is used to support compliance with applicable EMC requirements. The EMC test report can form part of the technical documentation supporting the EU Declaration of Conformity and CE marking.

CISPR 11 is also referenced by product-family standards. For example, IEC 61326-1 uses CISPR 11 for emissions requirements for measurement, control and laboratory equipment, while IEC 60601-1-2 uses CISPR 11 for emissions from medical electrical equipment and systems.

The Standard addresses both conducted and radiated electromagnetic disturbances. The applicable measurements depend on the equipment classification, ports, operating frequency, rated power, and test configuration.

Conducted emissions can apply to AC mains power ports, DC power ports, and wired network ports. Radiated emissions are evaluated at the applicable measurement distance and frequency range.

The equipment must first be classified as Group 1 or Group 2 and Class A or Class B, since this classification determines which emissions limits apply.

CISPR 11 covers equipment using RF energy over a broad frequency range. For Group 2 equipment, the standard defines intentional generation or local use of RF energy from 9 kHz to 400 GHz.

This range should not be confused with the frequency range over which emissions are measured. The required measurement range depends on the equipment, its operating frequency, classification, and the applicable CISPR 11 limits.

The tables below show examples of CISPR 11 limits for Group 1 equipment.
The applicable limits depend on the equipment class, port, rated power, measurement distance, and test configuration.

Example 1 – Conducted Emissions at the AC Mains Power Port

Example 2 – Radiated Emissions

These tables are provided as examples only. CISPR 11 includes additional limits for
Class A equipment, DC power ports, wired network ports, higher-power equipment,
FAR measurements, and radiated emissions above 1 GHz.

For emissions measurements, the equipment should be arranged and operated in a representative configuration. Cables, ports, peripheral equipment, grounding, and operating conditions that can influence the measured emissions should be considered when establishing the test configuration.

Operating modes should represent normal operation and exercise the functions that can produce the highest electromagnetic disturbances. Where several operating modes can significantly affect emissions, additional configurations or measurements may be required.

From our experience, radiated emissions below 1 GHz are a common failure point for ISM equipment. A pre-compliance scan can identify these problems early and allow design changes before formal CISPR 11 testing.