Council Directive 72/245/EEC (repealed)Show full title

[F1 ANNEX VIII U.K. METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM ELECTRICAL/ELECTRONIC SUB-ASSEMBLIES

Textual Amendments

F1 Substituted by Commission Directive 95/54/EC of 31 October 1995 adapting to technical progress Council Directive 72/245/EEC on the approximation of the laws of the Member States relating to the suppression of radio interference produced by spark-ignition engines fitted to motor 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.

1. General U.K.

1.1. The test method described in this Annex may be applied to ESAs. U.K.

1.2. Measuring apparatus U.K.

The measuring equipment shall comply with the requirements of publication No 16-1 (93) of the International Special Committee on Radio Interference (CISFR).

An average detector or a peak detector shall be used for the measurement of radiated narrowband electromagnetic emissions in this Annex.

1.3. Test method U.K.

1.3.1. This test is intended to measure the narrowband electromagnetic radiation such as might emanate from a microprocessor-based system. U.K.

1.3.2. As a short (2 to 3 minutes) initial step, choosing one antenna polarization, it is permitted to make sweeps of the frequency range identified in paragraph 6.1 of this Annex using a spectrum analyser to indicate the existence and/or whereabouts of peak emissions. This may assist in the choice of frequencies to be tested (see paragraph 6 of this Annex). U.K.

2. Expression of results U.K.

The results of measurements shall be expressed in dB microvolts/m (microvolts/m).

3. Measuring location U.K.

3.1. The test site shall comply with the requirements of publication No 16-1 (93) of the International Special Committee on Radio Interference (CISPR) (see Appendix 1 to Annex VII). U.K.

3.2. The measuring set, test hut or vehicle in which the measurement set is located shall be outside the boundary shown in Appendix 1 to Annex VII. U.K.

3.3. Enclosed test facilities may be used if correlation can be shown between the enclosed test facility and an outdoor site. Enclosed test facilities do not need to meet the dimensional requirements of Appendix 1 to Annex VII other than the distance from the antenna to the ESA under test and the height of the antenna (see Figures 1 and 2 of Appendix 2 to Annex VII). U.K.

3.4. Ambient U.K.

To ensure that there is no extraneous noise or signal of a magnitude sufficient to affect materially the measurement, measurements shall be taken before and after the main test. In both of these measurements, the extraneous noise or signal shall be at least 10 dB below the limits of interference given in paragraph 6.6.2.1 of Annex I, except for intentional narrowband ambient transmissions.

4. ESA state during tests U.K.

4.1. The ESA under test shall be in normal operation mode. U.K.

4.2. Measurements shall not be made while rain or other precipitation is falling on the ESA under test or within 10 minutes after rain or other precipitation has stopped. U.K.

4.3. Test arrangements U.K.

4.3.1. The ESA under test and its wiring harnesses shall be supported 50 ± 5 mm above a wooden or equivalent non-conducting table. However, if any part of the ESA under test is intended to be electrically bonded to a vehicle's metal bodywork, that part shall be placed on a ground plane and shall be electrically bonded to the ground plane. The ground plane shall be a metallic sheet with a minimum thickness of 0,5 mm. The minimum size of the ground plane depends on the size of the ESA under test but shall allow for the distribution of the ESA's wiring harness and components. The ground plane shall be connected to the protective conductor of the earthing system. The ground plane shall be situated at a height of 1,0 ± 0,1 m above the test facility floor and shall be parallel to it. U.K.

4.3.2. The ESA under test shall be arranged and connected according to its requirements. The power supply harness shall be positioned along, and within 100 mm of, the edge of the ground plane/table closest to the antenna. U.K.

4.3.3. The ESA under test shall be connected to the grounding system according to the manufacturer's installation specification, no additional grounding connections shall be permitted. U.K.

4.3.4. The minimum distance between the ESA under test and all other conductive structures, such as walls of a shielded area (with the exception of the ground plane/table underneath the test object) must be 1,0 m. U.K.

4.4. Power shall be applied to the ESA under test via a 5 μH/50 Ω resistance artificial network (AN) which shall be electrically bonded to the ground plane. The electrical supply voltage shall be maintained to ± 10 % of its nominal system operating voltage. Any ripple voltage shall be less than 1,5 % of the nominal system operating voltage measured at the AN monitoring port. U.K.

4.5. If the ESA under test consists of more than one unit, the interconnecting cables should ideally be the wiring harness as intended for use in the vehicle. If these are not available, the length between the electronic control unit and the AN shall be 1 500  ± 75 mm. All cables in the loom should be terminated as realistically as possible and preferably with real loads and actuators. If extraneous equipment is required for the correct operation of the ESA under test, compensation shall be made for the contribution it makes to the emissions measured. U.K.

5. Antenna type, position and orientation U.K.

5.1. Antenna type U.K.

Any linearly polarized antenna may be used provided it can be normalized to the reference antenna.

5.2. Height and distance of measurement U.K.

5.2.1. Height U.K.

The phase centre of the antenna shall be 50 ± 10 mm above ground plane.

5.2.2. Distance of measurement U.K.

The horizontal distance from the phase centre, or tip of the antenna as appropriate, to the edge of the ground plane shall be 1,00 ± 0,05 m. No part of the antenna shall be closer than 0,5 m to the ground plane. The antenna shall be placed parallel to a plane which is perpendicular to the ground plane and coincident with the edge of the ground plane along which the principal portion of the harness runs.

5.2.3. If the test is carried out in a facility enclosed for radio frequency electromagnetic screening purposes, the antenna's receiving elements shall be no closer than 0,5 m to any radio absorbent material and no closer than 1,5 m to the wall of the enclosed facility. There must be no absorbent material between the receiving antenna and vehicle electrical/electronic system under test. U.K.

5.3. Antenna orientation and polarization U.K.

At the measuring point, readings shall be taken both with the antenna in a vertical and in a horizontal polarization.

5.4. Readings U.K.

The maximum of the two readings taken (in accordance with paragraph 5.3) at each spot frequency shall be taken as the characteristic reading at the frequency at which the measurements were made.

6. Frequencies U.K.

6.1. Measurements U.K.

Measurements shall be made throughout the 30 to 1 000  MHz frequency range. This range shall be divided into 13 bands. In each band one spot frequency may be tested to demonstrate that the required limits are satisfied. To confirm that the ESA under test meets the requirements of this Annex, the testing authority shall test one such point in each of the following 13 frequency bands:

30 to 50, 50 to 75, 75 to 100, 100 to 130, 130 to 165, 165 to 200, 200 to 250, 250 to 320, 320 to 400, 400 to 520, 520 to 660, 660 to 820, 820 to 1 000  MHz. In the event that the limit is exceeded during the test, investigations shall be made to ensure that this is due to the ESA under test and not to background radiation.

6.2. If during the initial step which may have been carried out as described in paragraph 1.3 of this Annex, the radiated narrowband emissions for any of the bands identified in paragraph 6.1 are at least 10 dB below the reference limit, then the ESA shall be deemed to comply with the requirements of this Annex in respect of that frequency band.] U.K.