GB/T 3449-1994 Measurement of interior noise of railway locomotives and rolling stock
Some standard content:
UDC 534.6 : 625.23
National Standard of the People's Republic of China
GB/T 3449—94
Measurement of noise inside rail way vehicles
Measurement of noise inside rail way vehicles1994-07-19Promulgated
State Administration of Technical Supervision
Implementation on 1995-04-01
National Standard of the People's Republic of China
Measurement of noise inside rail way vehicles
Measurement of noise inside rail way vehicles1Subject content and scope of application
GB/T3449-94
Replaces 3449.2—85
GB3449.1—82
This standard specifies the conditions, methods and report contents for measuring the interior noise of the driver's cab and passenger cars of railway locomotives. This standard applies to the measurement of the interior noise of the driver's cab and passenger cars of railway diesel and electric locomotives. 2 Reference standards
GB3785 Electrical and acoustic performance and measurement methods of sound level meter GB3241 1/1 and 1/3 octave filters for sound and vibration analysis 3 Terms
3.1 Steady noisesteadynoise
Continuous noise composed of wheel-rail impact noise and noise from diesel engine and auxiliary units when locomotive or passenger car is running. 3.2 Intermittent noiseintermittent noiseintermittent noise added to the steady noise of the driver's cab, mainly refers to the noise of special sound sources such as whistle, exhaust (steam), etc. 3.3 Equivalent sound levelequivalentcontinuousA-weighted sound levelThe average value of the A-weighted sound level of steady noise and intermittent noise in the driver's cab or passenger car within eight hours according to energy. 4 Basic technical requirements
4.1 The measurement conditions for testing steady noise shall comply with the provisions of this standard. 4.2 The equivalent sound level measurement of the locomotive driver's cab shall be based on the test purpose and select representative measurement conditions in the section that can reflect the actual working conditions.
5 Measuring instruments
5.1 The noise should be measured using a sound level meter or integrating sound level meter of type no less than 1000mm, and its performance should comply with the provisions of GB3785. 5.2 The performance of the filter should comply with the provisions of GB3241. 5.3 The sound level meter should be calibrated with a sound level calibrator with an accuracy of no less than ±0.5dB before and after use. 5.4 The sound level meter and sound calibrator should be certified by the acoustic metrology department. 6 Measured quantity
6.1 The measured quantity is the "fast gear A sound level LpAF" in dB(A). 6.2 When spectrum analysis is required, the measured quantity is the octave band sound pressure level or the 1/3 octave band sound pressure level Li in dB. 6.3 When measuring the equivalent sound level in the locomotive cab and passenger car, a representative section should be selected to measure with an integrating sound level meter in dB(Le). At the same time, the following method is used to calculate the daily noise exposure time of the crew, that is, divide the total monthly cumulative noise exposure time by 25.5 to obtain the daily noise exposure time. Approved by the State Administration of Technical Supervision on July 19, 1994 and implemented on April 1, 1995.
7 Measurement location
7.1 Measurement location in the locomotive cab||tt ||GB/T3449-94
The microphone should be facing upwards and placed in the center of the driver's cab 1.2m above the floor. 7.2 Measurement position of passenger cars
7.2.1 Take 5 to 6 measurement points at both ends and the middle of the passenger car according to the ear height of the two groups of people in the sitting and standing positions (for sleeping cars, according to sleeping and standing positions); the measurement points on the upper and lower floors of double-decker buses are the same. For specific measurement point locations, see Appendix A (Supplement). 7.2.2 The microphone should be facing upwards during measurement.
8 Steady-state noise measurement readings
8.1 Each measurement lasts for no less than 5s. Read the middle value of the A sound level and take the nearest whole decibel. Values that are significantly different from general noise should be removed. If there is obvious pure tone or impulse noise that is difficult to remove, it should be explained in the measurement results. 8. 2 Each measuring point shall be measured three times, and the measurement result shall be expressed as the arithmetic mean of the three measured values (rounded to the nearest decibel according to the rounding rule). If the maximum difference between the three measurement data under the same conditions is greater than 3dB, the measurement shall be repeated. 9 Measurement conditions
9.1 Acoustic environment, meteorological conditions and background noise 9.1.1 There should be no large-scale continuous sound reflectors such as road cuts, hills, buildings, etc. near the sides of the track. There should be no snow or other sound-absorbing coverings adjacent to the track. If such coverings exist, they should be noted in the inspection report. 9.1.2 Meteorological conditions (wind, rain, snow, temperature, etc.) shall not affect the measurement results. 9.1.3 Background noise shall meet the following requirements
9.1.3.1 When testing steady-state noise, the background noise in the vehicle shall be lower than the test noise. Under the test conditions, the noise inside the car is more than 10dB lower; if the background noise inside the car is less than 10dB lower than the noise inside the car under the test conditions, it needs to be corrected according to the following table. dB
The decibel number of the background noise lower than the test sound level is added to the decibel number of the test sound level
9.2 Test route
Measurement invalid
9.2.1 The test section route is required to be straight, with a slope not exceeding 6%, dry and unfrozen gravel roadbed, wooden sleepers or concrete sleepers. When measuring, tunnels, bridges, forks, stations and trains should be avoided. 9.2.2 The track should be a standard short track or long track, and the track surface should not have obvious scratches, local defects and other abnormal defects. 9.3 Locomotive test conditions
9.3.1 The wheel tread should be free of scratches, peeling, falling blocks and other defects. 9.3.2 All doors and windows of the driver's cab must be closed tightly, and no more than 4 people should be allowed in the room. 9.3.3 The constant speed test vehicle speed is 90 ± 5 km/h (the traction truck speed is 70 ± 5 km/h), 2/3 rated power, and the auxiliary units are started (if the occurrence time is less than 1 minute, or its total sound level does not increase by 5dB, it can be ignored). 9.3.4 High-speed tests should be carried out at maximum speed and full load. 9.3.5 During the stationary test, the locomotive measurement conditions should meet the following requirements: 9.3.5.1 All units of the electric locomotive are started and the maximum load; if necessary, it can also be measured under the minimum speed and no-load conditions. 9.3.5.2 Diesel locomotives should be inspected under the following two conditions: a.
The lowest no-load stable speed of the diesel engine, the lowest speed of the fan, the minimum load of the auxiliary unit, and the air compressor is not working; the highest no-load stable speed of the diesel engine, the highest speed of the fan, the normal load of the auxiliary unit, and the full load of the air compressor. 9.4 Test conditions for buses
GB/T3449--94
9.4.1 The wheel tread should be free of defects such as scratches, peeling, and falling blocks. The distance between the test bus and the power car should be such that the noise of the power car does not affect the noise measurement of the test bus.
9.4.2 For constant speed test, the bus speed is 90±5km/h. When high-speed test is required, it should be carried out at the maximum speed. 9.4.3 All doors and windows of the test bus should be closed. The test should be carried out in an unmanned environment as much as possible. If this is not possible, the number of people in the bus should be indicated. 9.4.4 Facilities that have a significant impact on the noise in the bus, such as air-conditioning power devices, should be measured in the starting and stopping conditions respectively. 9.4.5· Stationary test, air-conditioned vehicles and powered buses should be tested under the rated load of the power device. 10
Inspection report
The inspection report shall include the following contents (see Appendix B (reference)): a.
Inspection object and nature;
Test section, line, track;
In-vehicle environment and meteorological conditions;
Measuring instruments;
Test working conditions;
A diagram showing the position of microphones;
Background noise;
“Fast” A sound level, noise spectrum when necessary; whether there is pure tone or impulse noise;
Equivalent sound level in the locomotive cab.
A1 car
See Figure A1.
GB/T3449-94
Appendix A
Measurement positions of various passenger cars
(Supplement)
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Figure A1 Measurement base position of seat car
Note: The three measurement points A, B, and C are respectively measured at a height of 1.1~1.2m and 1.5~1.6m from the floor. A2 Sleeper car
See Figure A2
Figure A2 Measurement position of sleeper car
Note: ①A, B, and C are 1.11.2m high from the floor. ②D, E, and F are 0.2m away from the side wall and 0.2m high from the pavement. A3 Dining car
See Figure A3.
Figure A3 Measurement position of dining cart
Note: DA and B are measured at 1.1~1.2m and 1.5~1.6m above the floor respectively. ②Point C is the geometric center of the kitchen, 1.5~1.6m high. A4 luggage cart
See Figure A4.
Figure A4 luggage cart measurement position
Note: ①A, B, C are 1.5~1.6m high from the floor. GB/T3449-94
②D is the office seat, 1.1~1.2m high from the floor; E is the geometric center of the office, 1.5~1.6m high from the floor. A5 postal car
See Figure A5.
Figure A5 postal car measurement position
Note: ①A, B, C are 1.5~1.6m high from the floor. ②D is the office seat, 1.11.2m high from the floor; E is the geometric center of the lounge, 1.5~1.6m high from the floor; F is the lower berth in the lounge, 0.2m away from the side wall and 0.2m high from the floor. A6 Combined vehicle
Measurement points shall be taken according to the above corresponding vehicle models.
Double-decker bus
See Figure A6.
Figure A6 Measurement position of the lower (or upper) floor of a double-decker bus Note: The three measurement points A, B, and C are respectively measured at a height of 1.1~1.2m and 1.5~1.6m from the floor. Appendix B
Noise measurement record form for the driver's cab or bus
(reference)
Measurement date
In-vehicle environment and meteorological conditions
Measuring instrument
Test object and nature
Test section, line and track
Presence of pure tone or pulse sound
Type and number of vehicles
Number of people in the vehiclewwW.bzxz.Net
Background noise| |tt||Measurement location
GB/T3449--94
Table B1 "Fast" A sound level measurement value
Measurement point height, m
A sound level measurement value, dB
Table B2 Stationary locomotive and passenger car noise spectrum analysis measurement Table 3
Octave or 1/3 octave center frequency sound pressure level, dB Working condition
Average value
10 000
Additional remarks:
GB/T344994
This standard was reviewed and approved by the National Technical Committee for Acoustics Standardization and the Ministry of Railways of the People's Republic of China. This standard was proposed and managed by the Noise Subcommittee of the National Technical Committee for Acoustics Standardization. This standard was drafted by the Institute of Labor Hygiene of the Ministry of Railways. The main drafters of this standard were Zheng Tianen and Wang Side. (Beijing) Xindengzi No. 023
People's Republic of China
National Standard
Measurement of Interior Noise of Railway Locomotives and Rolling Stocks
GB/T3449-94
Published by China Standards Press
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Printed by Qinhuangdao Printing Factory of China Standards Press Xinhua Distributed by Beijing Publishing House Sold by Xinhua Bookstores in all regions Copyright reserved Reproduction prohibited
Format 880×12301/16
Printing sheet 3/4 Word count 13,000 words
First edition December 1994
First printing December 1994
Print run 1-1500
Book number: 155066·1-11214 Price 3.00 yuan*
Heading 253-25
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