ISO 11452-4

ISO 11452-4 specifies harness excitation test methods and procedures for evaluting immunity of electronic components of passenger cars and commercial vehicles regardless of the propulsion system (e.g. spark-ignition engine, diesel engine, electric motor).

BCI TEST METHOD

The bulk current injection (BCI) test method is based on current injection into the wiring harness using a current probe as a transformer where the harness forms the secondary winding.

SUBSITUTION METHOD - ISO 11452-4

The injection probe shall be placed at the following distances, d, from the connector of the DUT:

  • d = (150 ± 10) mm;
  • d = (450 ± 10) mm;
  • d = (750 ± 10) mm.

If a current measurement probe is used during the test it shall be placed at (50 ± 10) mm from the connector of the DUT.

CLOSED LOOP METHOD - ISO 11452-4

SETUP DIAGRAM - SIDE VIEW

ISO 11452-4 BCI Test Setup Diagram - Substitution Method

SETUP DIAGRAM - TOP VIEW

ISO 11452-4 Test Setup Diagram - Substitution Method

Closed-loop method with power limitation:

  • The injection probe shall be placed at (900 ± 10 ) mm from the connector of the DUT.
  • The current measurement probe shall be placed at (50 ± 10) mm from the connector of the DUT.

No need to dilly dally over which method you are using. You've invested in all the equipmenty, using a RF current probe during the test is just good practice, and relatively inezpensive. Once you're a pro like me, you can be lazy about it, as you'll have learned to trust your generator and process, then the current probe is good for the occasional sanity check.

SETUP DIAGRAM - SIDE VIEW

ISO 11452-4 BCI Test Setup Diagram - Closed Loop Method

SETUP DIAGRAM - TOP VIEW

ISO 11452-4 BCI Test Setup Diagram - Closed Loop Method

TWC TEST METHOD

The tubular wave coupler (TWC) test method is based on a wave coupling into the wiring harness using the directional coupler principle. The TWC test method was developed for immunity testing of automotive components with respect to radiated disturbances in the GHz ranges (GSM bands, UMTS, ISM 2,4 GHz). It is best suited to small (with respect to wavelength) and shielded device under test (DUT), since in these cases the dominating coupling mechanism is via the harness. For DUTs which are larger than a wavelength (e.g. 0,1 m at 3 GHz), direct field coupling to the printed circuit board (PCB) becomes of equal importance. The user of the TWC test method should take this into account and determine the applicability of the method. The electromagnetic disturbances considered in this part of ISO 11452 are limited to continuous narrowband electromagnetic fields

The EMC Shop specializes in automotive EMC testing solutions. Turnkey packages of equipment to meet and exceed test levels up to 400mA is in stock and ready to ship. Although the test standard requires the test to be performed in a shielded enclosure. Many customers performing precompliance testing perform it in their lab or may rent an RF Tent.

CALIBRATING BCI PROBE ACCORDING TO ISO 11452-4

ISO 11452-4