1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE Do Not Use on New Programs. Being Replaced by GMW3091 EDS-T-5520 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 (Sup
2、erceded) EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 1/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project (incl. Variant Program). It is Sup
3、erceded for all future projects and replaced by GMW3091 1. PURPOSE This standard aims at specifying the methods of measuring narrowband electromagnetic emission from systems containing a microprocessor and other narrowband electromagnetic emission sources mounted in vehicles manufactured by GMDAT. T
4、he following shows some sources of narrowband electromagnetic emission: - System including digital logic - System including oscillator - System including clock generator 2. SCOPE This standard applies to all vehicles manufactured by GMDAT. 3. TEST SAMPLE (TEST VEHICLE) CONDITIONS At the normal tempe
5、rature, all functions of the test vehicle shall operate normally to meet design purposes. 4. DEFINITION OF TERMS 4.1. Narrowband electromagnetic emission Electromagnetic emission having smaller bandwidth than that of specific measuring instruments or receivers. 4.2. Open area test site : oats Test s
6、ite built to permit measuring of interference field intensity of electromagnetic waves radiated above the clear level ground that is free of objects reflecting electromagnetic waves, such as the surrounding building, electric cable, wall, tree, and underground cable and oil pipeline. 4.3. Substitute
7、 test laboratory (Semi-anechoic chamber) Facility designed to prevent reflection of electromagnetic wave by the electromagnetic wave absorbers installed on its boundary, it has the characteristics equivalent to the open area test site. 4.4. Ground plane A plane composed of the metal electric conduct
8、or or the conducting wire installed on the ground to acquire the same effect as grounding. 4.5. Ambient noise Radiated or transmitted noise that is present on a specific place without the object to be tested (test vehicle, etc.) being operated. EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND
9、ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 2/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology 4.6. Sweep Continuous change or change by a small increment throughout the frequency band. 4.7. Peak detector Detector whose output voltage is represented as
10、the peak value of applied signals 4.8. Frequency window It is defined as the span between the starting frequency and ending frequency used in measurement or data recording. It is also called frequency span when the spectrum analyzer is used. 4.9. Resolution bandwidth (RBW) Bandwidth of the filter us
11、ed for discerning the noise frequency coming from electrical/electronic devices, it is usually -3dB and may be -6dB depending on the specifications. 4.10. Impulse bandwidth Bandwidth of the rectangular filter that has the same voltage response as that of the filter actually used In case the spectrum
12、 analyzer is used in test procedures of this standard, the impulse bandwidth has the following relation with the resolution bandwidth (RBW). Impulse (bandwidth = 1.5(selected RBW) 5. MEASURING FACILITIES 5.1. The measuring facilities shall meet requirements in items 1 and 2 of “Electromagnetic inter
13、ference prevention test method” Chapter 2 General test conditions, Paragraph 2 Measuring facilities, Clause 8 General conditions of measuring facilities. Of the Clause 9, Bandwidth of measuring instrumentand Clause 12, Test standspecified in item 2, those related to the latterClause 12, Test standsh
14、all be excluded. * Note : Item 2 stipulates that particulars not specified in Clause 9, Bandwidth of measuring instrumentand Clause 12, Test stand of item 2 shall follow the recommendations of CISPR. 5.2. The measuring facilities used for test shall have been calibrated on a regular basis. 5.3. Type
15、 of measuring facilities 5.3.1. Spectrum analyzer, radio noise meter, EMI test receiver The spectrum analyzer can be used. In case a radio noise meter is used, an auxiliary device capable of measuring quasi-peak value shall be connected. When equipment having correlation with the spectrum analyzer i
16、s used, clause 5.1 shall be met. (1) Calibration: To ensure accuracy of measuring instruments, calibration shall be conducted regularly according to the calibration factor shown in the manual instruction. Other peripheral devices used in measurement (Ex. cable, antenna) shall be calibrated together.
17、 (2) Display units: The linear scale is convenient only for observing low signal level data. In the vast area as in this EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 3/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO
18、Auto & Technology test, the log scale is more appropriate, whose correlation is as follows: Level in dB V/m = 20*log10(Level in V/m) (3) Preamplifier: When very low level signals are detected or are likely to be detected, a preamplifier is used at the input end of the radio noise meter to improve th
19、e system sensitivity. When connected to the measuring instruments, double coaxial cable is required, and RF common-mode choke, such as ferrite core, may be inserted into the coaxial cable to reduce measuring error. (4) Instrumentation overload: Steps are provided to avoid overload of the preamplifie
20、r or radio noise meter. (5) Equipment noise floor: The noise floor of the measuring instrument shall be lower than the narrow band emission standard value of the test sample by 6dB. 5.3.2. Antenna (1) Biconical antenna 1) Frequency range : 20 KHz300 KHz 2) Reference point : Antenna center (2) Log-pe
21、riodic antenna 1) Frequency range : 300 KHz1000 KHz 2) Reference point : Antenna front end (3) Conical log-spiral antenna 1) Frequency range : 200 KHz1000 KHz 2) Reference point : Antenna front end (4) Any antenna may be used if it meets requirement for the reference antenna. (5) ForPreliminary prov
22、isional testin vehicle certification test, the antenna in the test vehicle shall be used. 5.3.3. Antenna master It shall be of the structure that permits change of the antenna height to the specified level and of the polarity to the vertically polarized and horizontally polarized waves and shall be
23、made of the non-conductive materials. 5.3.4. Impedance matching unit It is used when impedance matching with the test vehicle is required. 5.3.5. Antenna positioning controller It is used when the automatically adjustable antenna master is used in changing the antenna height and polarity. 5.3.6. Pro
24、cess controller It is used when the test is performed with the measuring instrument automatically adjusted through software. 5.3.7. Plotter or printer It is used to print out the measuring results. 6. TEST ENVIRONMENT (MEASURING PLACE) 6.1. Open area test site: The test in OATS shall be performed at
25、 the center of a 30 m radius level clear area EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 4/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology midway between the test vehicle and antenna which is free
26、 from electromagnetic interference as shown in Attachment 1. 6.2. The semi-anechoic chamber can only be used when compatible with the open area test site (when the test conditions are met). 6.3. When the test is performed in the open area test site, the measuring instrument, laboratory and the vehic
27、le for the measuring instrument shall stay in the permissible area within 15m as shown in Attachment 1. Other measuring antennas shall be at least 10m away from the reception antenna and vehicle. 6.4. When the test is performed in the semi-anechoic chamber, the test vehicle and antenna shall stay at
28、 least 0.5 m away from the absorber and at least 1.0m from the wall as shown in Attachment 2. 6.5. The surroundings of the open area test site shall be practically free from external noises or signals large enough to affect measuring. The external noise or signal shall basically be at least 6dB lowe
29、r than the radiant quantity limits in standard. However, this does not apply to cases in which the sum of the noise radiated from the test object (test vehicle) and ambient noise stays within the standard limits or where the electromagnetic wave from the test vehicle can be measured by other methods
30、 when the limits are exceeded at the specific frequency. 6.6. As shown in Attachment 2, preliminary provisional test for FM broadcasting frequency in vehicle certification test shall be conducted in the shielded room or semi-anechoic chamber. 7. TEST PROCEDURES 7.1. Test method 7.1.1. Preliminary ve
31、hicle check (1) Check if electric parts to be operated for each test item are actually installed. (2) Before commencing and upon completing the test, check the vehicle and mounted electric parts for normal operation. 7.1.2. Measuring instrument check and set-up (1) Warm up the measuring instrument f
32、or about 30 minutes before commencing the test. (2) Check the measuring instrument for presence of troubles and set-up condition (See Attachment 3). 1) Distance between the vehicle and antenna: 10m test : 10.00.2m, 3m test : 3.000.05m 2) Antenna height: 10m test : 3.000.05m, 3m test : 1.800.05m 3) A
33、ntenna position: Proceed with test while placing the antenna in front of, right of and left of the vehicle engine. 4) Antenna polarity: While changing the polarity both horizontally and vertically, measure the horizontal and vertical polarization. 7.1.3. Vehicle conditions during test EDS-T-5520METH
34、OD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 5/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology (1) While measuring, all electronic systems shall be in the operating mode with the vehicle in the stationary state.
35、(2) Ignition switch shall be ON. (3) Electric parts that are required to operate during test may be switched on depending on tests. (4) Test shall not be performed when the weather conditions affect the vehicle, such as rainy days. However, the test may be performed from 10 minutes after the rain st
36、ops. 7.1.4. Measuring (1) Check the ambient noise level. Ambient noise level check shall be conducted before and after the main test in order to confirm absence of external noises or signals large enough to affect measuring. (2) With the antenna placed in front of, right of and left of the vehicle e
37、ngine, conduct the test while varying the antenna polarity horizontally and vertically. (3) Of the 6 types of measurement reading for each frequency obtained according to the antenna position and polarity, have the largest as the representative value for the corresponding frequency. (4) Measuring fr
38、equency : Conduct measuring throughout the frequency band of 30MHz 1000MHz. (5) For the vehicle certification test, Preliminary provisional test shall be conducted with the test vehicle antenna for the FM broadcast reception frequency band of 88MHz 108MHz. If the measurement is below 20dBV , it is d
39、eemed meeting the standard for narrow band electromagnetic emission. (6) If the measurement is 20dBV or above inPreliminary provisional test, select a proper frequency for each of the following 13 frequency range sections between 30MHz and 1000MHz and perform measuring again. Measuring frequency ran
40、ge (MHz) 3050, 5075, 75100, 100130, 130165 , 165200, 200250 250320, 320400, 400520, 520660, 660820, 8201000 (7) Measuring unit : dBV/M (V/M) (8) At measuring, peak detector 120 KHz bandwidth shall serve as the basis. 7.1.5. Result recording Arrange the measuring results according to Attachment 6 Veh
41、icle narrow band electromagnetic emission measuring data sheet. 7.2. Test standard 7.2.1. For both measuring distance of 10m and 3m, the values 2dBV/M below the standard limits (below standard limits 20% when V/M is used) specified in Appendix 3 “Narrow band electromagnetic emission prevention stand
42、ard for automobiles, etc” of Electromagnetic interference prevention standard (same as 95/94/EC regulations) shall be made the standard limits for GMDAT. Here, the measuring frequency shall cover the entire frequency band of 30MHz 1000MHz. 7.2.2. For tests after the main test, the values +2dBV/M bel
43、ow the standard limits (below +20% when V/M is used) shall be made the standard limits for GMDAT. Here, the measuring frequency shall cover the entire frequency band of 30MHz 1000MHz. EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 6/11 ISSUED DATE
44、: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology 7.2.3. Standard limits of narrow band electromagnetic emission Based on peak detector, band width 120 KHz (1) Standard limits at measuring distance of 10m and antenna height of 3m (See Attachment 4) 30MHz 75MHz : 24dBV/
45、M Reference value L=24 75MHz 400MHz : 2435dBV/M Reference value L= 24 + 15.131log(f/75) 400MHz 1000MHz : 35dBV/M Reference value L=25 (2) Standard limits at measuring distance of 3m and antenna height of 1.8m (See Attachment 5) 30MHz 75MHz : 34dBV/M Reference value L=34 75MHz 400MHz : 3445dBV/M Refe
46、rence value L = 34 + 15.131log(f/75) 400MHz 1000MHz : 45dBV/M Reference value L=45 (3) Only one standard limit is applied according to the tested measuring distance and antenna height. (4) Exceptions to application of standard limits: In case the oscillation frequency of electric parts mounted in th
47、e vehicle is less than 9KHz, it is deemed meeting the narrow band electromagnetic emission requirements. 8. RELATED STANDARDS 8.1. “Electromagnetic interference prevention test method”, Chapter 2 General test conditions, Paragraph 2 Measuring facilities, Clause 8 General conditions of measuring faci
48、lities, items 1 and 2 8.2. “Electromagnetic interference prevention test method”, Chapter 2 General test conditions, Paragraph 2 Measuring facilities, Clause 9 Bandwidth of measuring instrument. 8.3. Electromagnetic interference certification: Appendix 3 “Narrow band electromagnetic emission prevent
49、ion standard for automobiles, etc” 8.4. 95/94/EC Annex V: Method of measurement of radiated narrow band electromagnetic emissions from vehicle EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FROM VEHICLE PAGE: 7/11 ISSUED DATE: 1994. 11. 11 REVISED DATE: 2008. 11. 04 VERSION: 4 GM DAEWOO Auto & Technology Attachment 1. Open Area Test Site (OATS) EDS-T-5520METHOD OF MEASUREMENT OF RADIATED NARROWBAND ELECTROMAGNETIC EMISSIONS FRO
