JB/T 6268-1992 Self-propelled harvesting machinery noise determination method JB/T6268-1992 standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T6268-1992
Self-propelled harvester
Noise determination method
Published on June 10, 1992
Implementation of the Ministry of Machinery and Electronics Industry of the People's Republic of China on July 1, 1993
Mechanical Industry Standard of the People's Republic of China
Self-propelled harvester
Noise determination method
Subject content and scope of application
This standard specifies the determination method of dynamic environmental noise and driver ear position noise of self-propelled harvester. This standard applies to self-propelled harvester. Reference Standard
GB3785
Electrical and acoustic performance and test method of sound level meter 3 Basic requirements
3.1 Before and after the test, the sound level meter shall be calibrated with an acoustic calibrator with an accuracy of ±0.5dB (A). JB/T 6268-1992
3.2 During the test, each measurement data must be accurate and reliable. If abnormal data is found, the cause should be found out in time and necessary treatment should be taken.
Instruments and equipment
a. Sound level meter, which should comply with the relevant provisions of GB3785; b. Anemometer;
c. Tape measure (20m);
d. Tachometer;
e. Timer;
f. Signal flag.
5 Test conditions
5.1 Meteorological conditions
The weather is good, the ambient temperature is -5~30℃, and the average wind speed is not more than 5m/s at 1.2m above the ground. When the wind speed is greater than 1m/s, a wind shield should be used, and it should not significantly affect the measurement accuracy. 5.2 Background noise
The background noise (including wind noise) during the test should be 10dB (A) lower than the total noise measured. 5.3 Acoustic environment
5.3.1 The test site should be flat and open. There should be no reflective objects such as buildings, solid walls, trees, machinery and equipment, and vehicles within a radius of not less than 50m. When limited by the test site, a radius of not less than 25m is allowed for small machines. The center of the dynamic environmental noise test site should have a straight, dry concrete, asphalt or similar hard material road surface of more than 20m, excluding sound-absorbing surfaces such as snow, grass and cinders.
There should be no obstacles that affect the acoustic field near the microphone, and there should be no people between the microphone and the noise source. Instrument observer Approved by the Ministry of Machinery and Electronics Industry on June 10, 1992 and implemented on July 1, 1993
The position should not affect the test results.
5.4 Machine conditions
JB/T6268-1992
5.4.1 The self-propelled harvester to be tested shall meet the technical parameters specified by the manufacturer, and all moving parts shall be operated in accordance with the manufacturer's instruction manual. The machine shall be unloaded, such as an empty grain tank without counterweight. 5.4.2 The engine shall quickly reach normal operating temperature before testing. 5.4.3 The tires on the machine shall meet the requirements of the manufacturer's instruction manual, and the wear shall not exceed 30% of the tread height. 6 Test method
6.1 Determination of dynamic environmental noise
6.1.1 See the figure below for a schematic diagram of the test site. The centerline CC of the runway shall be marked on the runway. The centerline of the runway is perpendicular to and passes through the centerline PP of the test site. The start line AA and the end line BB are parallel to the PP line and 100m away from it. The microphone is placed on the PP line, 7.5m away from the centerline CC and 1.2m above the ground. The microphone should be facing the test machine. 6.1.2 During the test, the centerline of the machine shall be on the centerline of the runway. The machine shall drive smoothly into the AA line at three-quarters of the maximum speed. When the front end of the machine reaches the AA line, immediately increase the throttle to the maximum position and keep it until the rear of the machine passes the BB line. 6.1.3 Use the "A" weighting network and "fast" gear of the sound level meter for measurement. The test shall be measured at least twice in both directions. When the machine passes through the measurement area, record the maximum sound level reading. The measured data is valid when the difference between the two measurement results on the same side of the machine is not greater than 2dB (A). om咖
Microphone
Microphone
Figure Schematic diagram of the layout of the test site for dynamic environmental noise measurement 6.2 Driver ear position noise measurement
6.2.1 During the test, the machine shall be fixed on the test site or short grass that meets the requirements of Article 5.3.1. The engine is running at the rated speed. When measuring the noise of machines equipped with a cab, all doors and windows shall be closed. A maximum of two people are allowed in the cab during the test. 6.2.2 During the measurement, the microphone is placed on the helmet frame of the driver and fixed horizontally forward on the side with more noise and 200±20mm from the center plane of the seat. The center of the microphone should be 790±50mm above the seat reference point and 150±20mm in front. The microphone should avoid excessive vibration. 6.2.3 Use the "A" weighting network and "slow" gear of the sound level meter for measurement. Under stable operation, measure once every 5s for a total of 3 times and calculate the arithmetic mean. The difference between the three readings should be less than or equal to 3dB (A). If it is greater than 3dB (A), it should be measured again. 2
Test records and results
JB/T 6268-1992
The test conditions,
measurement data and calculation results are recorded in the self-propelled harvester noise measurement record table (see the table below). Self-propelled harvester noise measurement record table Machine model and name:
Test date:
Test location:
Wind speed, m/s:
Engine type:
Cab type:
Sound level meter model:
Environmental background noise, dB (A):
Measurement location
Driver
Ear position noise
Sound measurement
Additional instructions:
Maximum noise value
Measurement point number
This standard is proposed and managed by the Chinese Academy of Agricultural Mechanization Sciences. This standard is drafted by the Chinese Academy of Agricultural Mechanization Sciences. The main drafters of this standard are Ma Hengqi and Hong Liangchen. Manufacturer:
Machine factory number:
Test site type:
Ambient temperature, ℃:
Rated engine speed, r/min:
Name of accessories used:
Background noise in the cab, dB (A):
dB (A)
People's Republic of China
Mechanical Industry Standard
Self-propelled harvesting machinery
Noise determination method
JB/T62681992
Published and distributed by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Sheet 1/2
Format 880×1230
Word count 6,000
First edition in March 1993
First printing in March 1993
Print run 1-500bzxZ.net
Price 2.00 yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_8929
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