Industrial, scientific and medical (ISM) radio-frequency equipment – Electromagnetic disturbance characteristics – Limits and methods of measurement
CISPR 11 is a broadly used international standard for electromagnetic compatibility within Europe for electromagnetic emissions or disturbances from Industrial, Scientific, and Medical, ISM, Equipment. CISPR 11 is conserved by CISPR: the International Special Committee on Radio Interference. It has grown from a simple document to a complex document involving a number of types of products
CISPR 11 applies to a very huge variety of equipment including everything from Wi-Fi systems, microwaves through to arc welders, all of which fall into the industrial, scientific and medical category which can use the ISM license-free bands like 2.4 GHz.
CISPR 11, EN 55011 is a standard covering radiated and conducted emissions. Most products will require an assessment of immunity standards, such as EN 61326-1: Electrical equipment for measurement, control and laboratory use; or EN 61000-6-2: Generic Standards Immunity for industrial environments.
It has grown from measuring products at a larger distance (100 meters and 30 meters) for Class A Equipment to measuring them at 3 meters. Class B equipment measurement distances have seen an equivalent degradation of “far-field” radiated emission measurements. This steady erosion of the “laws of physics” is worrisome and a trend to reverse this erosion is overdue in the engineering field of EMC and the EMC Standards arena.
List of tests
Conducted emissions input power
Harmonic current emissions
Voltage fluctuation & flicker
Electrostatic discharge immunity test
Radiated, radio-frequency, electromagnetic field immunity test
CISPR 32 is a discrete standard formed for Multimedia Equipment having a rated AC or DC supply voltage not exceeding 600 V, but equipment within the scope of CISPR 22 or CISPR 13 is also within the scope of this publication. It incorporates a range of functions which include those in ITE (Information technology), broadcasting, audio, and video equipment. It also includes entertainment lighting control equipment.
In this contemporary world, ITE performs many different functions, features, and capability which were assessed by different compliance standards but now CISPR 32 is a single standard which addresses the case where all different features are integrated instead of having separate compliance standards. This standard is adopted by the European Union.
Two classes of End-User Terminal Equipment Under Test EUT (Class A and Class B) are considered.
The aims of the standard are:
To establish requirements which provide an adequate level of protection of the radio spectrum allowing radio services to operate as intended in the frequency range 9 kHz to 400 GHz;
To specify procedures to ensure the reproducibility of measurement and the repeatability of results.
LIMITS AND METHODS OF MEASUREMENT OF RADIO DISTURBANCE CHARACTERISTICS OF ELECTRICAL LIGHTING AND SIMILAR EQUIPMENT
Reference standards for Immunity test in CISPR 15
This test simulates electrostatic events and evaluates the ability of the EUT to tolerate such events. Testing is performed in accordance with IEC/EN 61000-4-2. All accessible enclosure surfaces and ports are evaluated unless specified as a static-sensitive surface.
IEC 61000-4-2: 2008
Electromagnetic Compatibility—Testing and measurement techniques – Electrostatic discharge immunity test
The Electromagnetic Susceptibility test exposes the equipment under test to a calibrated uniform field of radiated electromagnetic energy. The EUT is continuously monitored while exposed to the required frequency range and field strength. The test chamber, radiating antennas, and calibrated fields meet the requirements of referenced standards
IEC 61000-4-3: 1996
Radio Frequency Immunity
Electromagnetic Compatibility—Testing and measurement techniques – Radiated radiofrequency electromagnetic field immunity test
Electrical Fast Transient
This test injects a transient/burst interference onto the Mains input power supply and signal I/O lines. The EUT and peripherals are placed on a non-conductive support platform, 10cm above the test ground plane. The EUT is monitored for disturbances during the required exposure time of positive and negative bursts
IEC 61000-4-4: 1995-01 Electrical Fast Transient Immunity
Electromagnetic Compatibility—Testing and measurement techniques – Electrical fast transient/burst immunity
This test simulates a lightning event by inducing transients onto the AC/DC power supply lines in common and differential mode. Testing is performed in accordance with IEC/EN 61000-4-5. The product-specific standard determines the minimum requirement for the exposure to surge transient levels
IEC 61000-4-5: 1995-02 Surge Immunity
Electromagnetic Compatibility—Testing and measurement techniques – Surge immunity test
Conducted RF Immunity
This test injects a disturbance directly onto AC/DC power. Testing is performed in accordance with IEC/EN 61000-4-6. The product-specific standard sets the level, duration, and the frequency range to apply.
IEC 61000-4-6: 1996-04 RF Common Mode Immunity
Electromagnetic Compatibility—Testing and measurement techniques – Immunity to conducted disturbances, induced by radio-frequency fields
This test subjects the EUT to power network faults and “brownouts”. Testing is performed in accordance with IEC/EN 61000-4-11. The EUT is powered up to a nominal voltage, and then software controlled voltage dips and interruptions are introduced
Voltage Dips and Short Interruptions
Electromagnetic Compatibility—Testing and measurement techniques – Voltage dips, short interruptions and voltage variations immunity tests
Device Performance Criteria for Immunity Tests
Criterion A – The equipment shall continue to operate as intended without operator intervention. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer when the equipment is used as intended. The performance level may be replaced by a permissible loss of performance. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, then either of these may be derived from the product description and documentation, and by what the user may reasonably expect from the equipment if used as intended.
Criterion B – During the test, the degradation of performance is allowed. However, no change in the operating state or stored data is allowed to persist after the test. After the test, the equipment shall continue to operate as intended without operator intervention. The performance level may be replaced by a permissible loss of performance. If the manufacturer does not specify the minimum performance level (or the permissible performance loss), then either of these may be derived from the product description and documentation, or by what the user may reasonably expect from the equipment if used as intended.
Criterion C – Loss of function is allowed, provided the function is self-recoverable or can be restored by the operation of the controls by the user in accordance with the manufacturer’s instructions. Functions, and/or information stored in non-volatile memory, or protected by a battery backup, shall not be lost. For each test method, the test standard specifies the appropriate criterion to be met.
This test measures the levels emanating from the EUT into the AC Mains, evaluating the potential for the EUT to cause radio frequency interference to other electronic devices. The EUT is configured based upon the requirements of the applicable test standard.
This test measures the levels emanating from the EUT, thus evaluating the potential for the EUT to cause radio frequency interference to other electronic devices. Measurement methods is used in accordance with the test standard(s) referenced. The antenna is positioned at several heights while the EUT is rotated 360°. At each antenna height, the receiver scans and records the maximum peak emissions. From the recorded scans, a list of discrete frequencies is developed for that antenna polarity. The antenna is then rotated in polarity and the scan repeated. For each discrete frequency, the turntable is rotated to the determined worst angle and the receive antenna is varied in height from one to four meters for the final maximum emissions. For EUT’s with auto-ranging power supplies, a pre-scan evaluation may be performed to determine “worst-case” radiated emissions.
CISPR 22 (An EMC standard for Information Technology (IT) Equipment)
CISPR 22 for Radio Disturbance Characteristics-Limits and Methods of Measurement. Applicable for IT equipment with a rated supply voltage not exceeding 600 V.
ITC India Pvt Ltd is a NABL approved lab in electronics, electrical and photometry. BIS approved for all lighting products and TEC approved for Electronics. We are performing EMI/EMC testing on electromedical, IT equipment, lighting, Laboratory, and household product. Testing is conducted in a shielding room.
CISPR 22 is accepted by most members of the European Community.
CISPR 22 discriminates between Class A and Class B equipment and it gives figures for conducted and radiated emissions for each class. In addition, CISPR 22 requires certification over the frequency range of 0.15 MHz to 30 MHz for conducted emissions. CISPR limits are provided in dBµV