[F1ANNEX IX U.K. METHOD(S) OF TESTING FOR IMMUNITY OF ELECTRICAL/ELECTRONIC SUBASSEMBLIES TO ELECTROMAGNETIC RADIATION
Textual Amendments
F1 Substituted by Commission Directive 2004/104/EC of 14 October 2004 adapting to technical progress Council Directive 72/245/EEC relating to the radio interference (electromagnetic compatibility) of vehicles and amending Directive 70/156/EEC on the approximation of the laws of the Member States relating to the type-approval of motor vehicles and their trailers (Text with EEA relevance).
1. General U.K.
1.1. The test method(s) described in this Annex may be applied to ESAs. U.K.
1.2. Test methods U.K.
1.2.1. ESAs may comply with the requirements of any combination of the following test methods at the manufacturer's discretion provided that this results in the full frequency range specified in paragraph 3.1 of this Annex being covered. U.K.
Absorber chamber test: according to ISO DIS 11452-2: 2003
TEM cell testing: according to ISO 11452-3: 3rd edition 2001
Bulk current injection testing: according to ISO DIS 11452-4: 2003
Stripline testing: according to ISO 11452-5: 2nd edition 2002
800 mm stripline: according to paragraph 4.5 of this Annex
(Frequency range and general test conditions shall be based on ISO DIS 11452-1: 2003).
2. State of ESA during tests U.K.
2.1. The test conditions shall be according to ISO 11452-1: 2002. U.K.
2.2. The ESA under test shall be switched on and must be stimulated to be in normal operation condition. It shall be arranged as defined in this Annex unless individual test methods dictate otherwise. U.K.
2.3. Any extraneous equipment required to operate the ESA under test shall not be in place during the calibration phase. No extraneous equipment shall be closer than 1 m from the reference point during calibration. U.K.
2.4. To ensure reproducible measurement results are obtained when tests and measurements are repeated, the test signal generating equipment and its layout shall be to the same specification as that used during each appropriate calibration phase. U.K.
2.5. If the ESA under test consists of more than one unit, the interconnecting cables should ideally be the wiring harnesses as intended for use in the vehicle. If these are not available, the length between the electronic control unit and the AN shall be as defined in the standard. All cables in the wiring harness should be terminated as realistically as possible and preferably with real loads and actuators. U.K.
3. General test requirements U.K.
3.1. Frequency range, dwell times U.K.
Measurements shall be made in the 20 to 2 000 MHz frequency range with frequency steps according to ISO 11452-1: 2002.
The test signal modulation shall be:
AM, with 1 kHz modulation and 80 % modulation depth in the 20-800 MHz frequency range,
PM, t on 577 μs, period 4 600 μs in the 800- 2 000 MHz frequency range,
if not otherwise agreed between technical service and ESA manufacturer.
Frequency step size and dwell time shall be chosen according to ISO 11452-1: 2001.
3.2. The technical service shall perform the test at the intervals specified in ISO DIS 11452-1: 2003 throughout the frequency range 20 to 2 000 MHz. U.K.
Alternatively, if the manufacturer provides measurement to data for the whole frequency band from a test laboratory accredited to the applicable parts of ISO 17025 (1st edition 1999) and recognised by the Approval Authority, the technical service may choose a reduced number of spot frequencies in the range, e.g. 27, 45, 65, 90, 120, 150, 190, 230, 280, 380, 450, 600, 750, 900, 1 300 and 1 800 MHz to confirm that the ESA meets the requirements of this Annex.
3.3. If an ESA fails the tests defined in this Annex, it must be verified as having failed under the relevant test conditions and not as a result of the generation of uncontrolled fields. U.K.
4. Specific test requirements U.K.
4.1. Absorber chamber test U.K.
4.1.1. Test method U.K.
This test method allows the testing of vehicle electrical/electronic systems by exposing an ESA to electromagnetic radiation generated by an antenna.
4.1.2. Test methodology U.K.
The ‘ substitution method ’ shall be used to establish the test field conditions according to ISO DIS 11452-2: 2003.
The test shall be performed with vertical polarisation.
4.2. TEM cell testing U.K.
4.2.1. Test method U.K.
The TEM (transverse electromagnetic mode) cell generates homogeneous fields between the internal conductor (septum) and housing (ground plane).
4.2.2. Test methodology U.K.
The test shall be performed according to ISO 11452-3: 3rd edition 2001.
Depending on the ESA to be tested the testing authority shall choose the method of maximum field coupling to the ESA or to the wiring harness inside the TEM cell.
4.3. Bulk current injection testing U.K.
4.3.1. Test method U.K.
This is a method of carrying out immunity tests by inducing currents directly into a wiring harness using a current injection probe.
4.3.2. Test methodology U.K.
The test shall be performed according to ISO DIS 11452-4: 2003 on a test bench. As an alternative the ESA may be tested while installed in the vehicle according to ISO 11451-4 (1st edition 1995).
The injection probe shall be positioned in 150 mm distance to the ESA to be tested.
The reference method shall be used to calculate injected currents from forward power.
The frequency range of the method is limited by the injection probe specification.
4.4. Stripline testing U.K.
4.4.1. Test method U.K.
This test method consists of subjecting the wiring harness connecting the components in an ESA to specified field strengths.
4.4.2. Test methodology U.K.
The test shall be performed according to ISO 11452-5 (2nd edition 2002).
4.5. 800 mm stripline testing U.K.
4.5.1. Test method U.K.
The stripline consists of two parallel metallic plates separated by 800 mm. Equipment under test is positioned centrally between the plates and subjected to an electromagnetic field (see Appendix 1 to this Annex).
This method can test complete electronic systems including sensors and actuators as well as the controller and wiring loom. It is suitable for apparatus whose largest dimension is less than one third of the plate separation.
4.5.2. Test methodology U.K.
4.5.2.1. Positioning of stripline U.K.
The stripline shall be housed in a screened room (to prevent external emissions) and positioned 2 m away from walls and any metallic enclosure to prevent electromagnetic reflections. RF absorber material may be used to damp these reflections. The stripline shall be placed on non-conducting supports at least 0,4 m above the floor.
4.5.2.2. Calibration of the stripline U.K.
A field-measuring probe shall be positioned within the central one third of the longitudinal, vertical and transverse dimensions of the space between the parallel plates with the system under test absent.
The associated measuring equipment shall be sited outside the screen room. At each desired test frequency, a level of power shall be fed into the stripline to produce the required field strength at the antenna. This level of forward power, or another parameter directly related to the forward power required to define the field, shall be used for type-approval tests unless changes occur in the facilities or equipment, which necessitate this procedure being repeated.
4.5.2.3. Installation of the ESA under test U.K.
The main control unit shall be positioned within the central one third of the longitudinal, vertical and transverse dimensions of the space between the parallel plates. It shall be supported on a stand made from non-conducting material.
4.5.2.4. Main wiring loom and sensor/actuator cables U.K.
The main wiring loom and any sensor/actuator cables shall rise vertically from the control unit to the top ground plate (this helps to maximise coupling with the electromagnetic field). Then they shall follow the underside of the plate to one of its free edges where they shall loop over and follow the top of the ground plate as far as the connections to the stripline feed. The cables shall then be routed to the associated equipment, which shall be sited in an area outside the influence of the electromagnetic field, e.g. on the floor of the screened room 1 m longitudinally away from the stripline.
Appendix 1
Figure 1 800 mm stripline testing U.K.
Figure 2 800 mm stripline dimensions U.K.
Appendix 2
Typical TEM cell dimensions U.K.
The following table shows the dimensions for constructing a cell with specified upper frequency limits:
| Upper frequency (MHz) | Cell form factor W:b | Cell form factor L/W | Plate separation b (cm) | Septum S (cm) |
|---|---|---|---|---|
| 200 | 1,69 | 0,66 | 56 | 70 |
| 200 | 1,0 | 1 | 60 | 50] |