What Is ISO 11452?
The ISO 11452 series defines test methods for evaluating the immunity of vehicle electrical and electronic components to radiated and conducted narrowband RF interference. It contains different sections such as anechoic chamber, TEM cell, strip line, BCI and single antenna.
Purpose of ISO 11452
The purpose is to verify that the component operates safely and correctly under RF sources on the vehicle and in the environment.
Which Products Is ISO 11452 Applied To?
- Electronic control units
- Sensors and actuators
- Instrument and infotainment modules
- Electric drive components
- Charging systems
In Which Sectors Is ISO 11452 Used?
Standards Related to ISO 11452
- ISO 11452-1radiated field immunity in vehicles test
- ISO 11452-2radiated field immunity in vehicles test
- ISO 11452-3radiated field immunity in vehicles test
- ISO 11452-4radiated field immunity in vehicles test
- ISO 11452-5radiated field immunity in vehicles test
- ISO 11452-11radiated field immunity in vehicles test
- UNECE R10electromagnetic compatibility in vehicles test
ISO 11452 Conditions
- ISO 11452-2
- Radiated immunity with antenna in anechoic chamber
- ISO 11452-3
- TEM cell method
- ISO 11452-4
- Current injection (BCI) into the wiring harness
- ISO 11452-5
- Strip line method
- Field strength/current
- Defined in the specification; OEM specifications set their own levels
Equipment for ISO 11452
- Anechoic chamber and antennas
- TEM cell and strip line layout
- BCI current injection probe and monitoring probe
- RF power amplifiers
- Function-monitoring system
Sample Requirements for ISO 11452
- Wire harness length and layout must comply with the standard
- Function monitoring and acceptance criteria class must be defined
- Load simulators must be documented
- The most sensitive operating mode should be determined
Duration of ISO 11452
It depends on the number of sections and frequency range applied; typically one to three business days.
ISO 11452 Procedure
- 1The ISO 11452 sections to be applied are determined.
- 2The sample, wiring harness and load simulator are set up.
- 3The test level is set with calibration data.
- 4The frequency band is scanned step by step.
- 5The function is constantly monitored and disturbances are recorded.
- 6The results are evaluated according to the acceptance criterion class.
ISO 11452 Acceptance Criteria
Acceptance criteria are given according to classes A, B, C, D, E defined in ISO 11452-1. Class A is generally required for safety-related functions.
Evaluation of Results
The frequency, level and method at which the distortion occurs are recorded. The results are not interchangeable because different methods reveal different coupling mechanisms.
ISO 11452 Report
- Standard sections and levels applied
- Frequency range and modulation
- Test pattern and wiring harness information
- Function observations and acceptance class result
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- UNECE R10
- Automotive OEM EMC specifications
EMC / EMI Testleri — What Does This Testing Field Cover?
The section below describes the field that the ISO 11452 test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
EMC testing answers a question with two sides: does the device emit an unacceptable level of electromagnetic interference into its surroundings (emission), and does it withstand the interference coming from them (immunity)? The two sides are measured with separate tests and separate set-ups, and both are required.
The field exists because of a simple physical fact: every conductor carrying current behaves like an antenna. A switched-mode power supply, a motor drive or the clock signal of a microcontroller radiates radio frequency energy even though it was never designed to. The same conductor also works in reverse: an external field induces a voltage across it. In an environment crowded with devices, this mutual effect means devices disturbing one another.
On the emission side, conducted and radiated emission are measured separately. Conducted emission is the interference the device imposes on its mains and communication cables and dominates at lower frequencies. Radiated emission is the field the device releases into the air and comes to the fore at higher frequencies. The two are measured in different set-ups, and the limits vary by product group.
On the immunity side, real-world sources of interference are simulated: electrostatic discharge (human touch), radiated radio frequency fields (a nearby transmitter), electrical fast transients (switching), surges (lightning and mains events), conducted radio frequency, power-frequency magnetic fields, voltage dips and short interruptions.
The standard to be applied depends on WHERE the product is used, and that choice determines the entire outcome. Residential and industrial environments carry different sets of limits; in vehicles the UNECE R10 regime applies rather than CE; for medical devices IEC 60601-1-2 brings additional requirements; and for products containing a radio, radio legislation comes into play and harmonised ETSI standards are used.
In immunity testing the acceptance criterion is a PERFORMANCE CRITERION class, not a binary pass/fail. A device continuing to function without interruption during the test, being temporarily affected and recovering by itself, or recovering only through user intervention are different classes. Which class is acceptable is defined in the product standard; the tolerance for a device carrying a safety function differs from that of a consumer device.
The most common shortcoming of an EMC file is that it covers only one side. A file carrying an emission report alone is not complete in terms of the EMC directive. The second common gap is a test set-up that does not represent actual use: if the device is measured on a bare bench with cables different from its real ones, the result does not carry over to the field.
Method groups in this field
Conducted emission
Interference imposed on the cable through mains and communication ports, measured via an artificial mains network (LISN).
Radiated emission
The field released into the air by the device, measured at a defined distance in an anechoic or semi-anechoic chamber.
Harmonics and flicker
The harmonic content of the current drawn from the mains and voltage fluctuation; the side that affects mains quality.
Electrostatic discharge
Contact and air discharge together with indirect discharge; the most frequently applied immunity test.
Radiated and conducted RF immunity
The device is exposed to a defined field strength and to an RF signal injected into the cable.
Mains-borne events
Electrical fast transients, surges, voltage dips and short interruptions.
Commonly confused in this field
- An emission report alone does not complete an EMC file; immunity must be demonstrated as well.
- An FCC report is not accepted in a CE file; the limits, measurement distances and set-ups are different.
- The EMC Directive does not apply to vehicles; the UNECE R10 regime does. Specifications requiring both together should be reviewed.
- The warning that a Class A device may cause interference in a residential environment is mandatory in the manual; market surveillance checks that this warning is present.
- The test set-up is part of the report. If cable type, length or routing changes, the result changes; measurement must be made in the series-production configuration.
- CISPR 22 and CISPR 13 have been withdrawn; their current counterparts are CISPR 32 and CISPR 35.
Which decisions these results support
- CE declaration under the EMC Directive
- The EMC part of radio equipment conformity
- A UNECE R10 file for a vehicle component
- Resolving field interference complaints and correcting the design
- Assessing the EMC impact of a board or wiring-harness change
Related Tests
Frequently Asked Questions About ISO 11452
According to which standard is ISO 11452 made?
ISO 11452 is executed in scope ISO 11452-1, ISO 11452-2, ISO 11452-3, ISO 11452-4, ISO 11452-5, ISO 11452-11 and UNECE R10. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does ISO 11452 apply to?
Mainly applied to Electronic control units, Sensors and actuators, Instrument and infotainment modules, Electric drive components and Charging systems. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is ISO 11452 done?
The determining parameters are: ISO 11452-2 — Radiated immunity with antenna in anechoic chamber, ISO 11452-3 — TEM cell method and ISO 11452-4 — Current injection (BCI) into the wiring harness. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for ISO 11452?
Wire harness length and layout must comply with the standard, Function monitoring and acceptance criteria class must be defined and Load simulators must be documented. The number of samples is determined according to the product standard and the scope to be reported.
How long does ISO 11452 take?
It depends on the number of sections and frequency range applied; typically one to three business days. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the ISO 11452 result called "appropriate"?
Acceptance criteria are given according to classes A, B, C, D, E defined in ISO 11452-1. Class A is generally required for safety-related functions.