JB/T 7232-1994 Simple method for determination of sound power level of packaging machinery noise
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T7232--94
Determination of the sound power level of packaging machinery noise
Simplified method
Published on July 18, 1994
Published by the Ministry of Machinery Industry of the People's Republic of China
Implemented on July 1, 1995
Mechanical Industry Standard of the People's Republic of China
Determination of the sound power level of packaging machinery noise
Simplified method
1 Subject content and scope of application
JB/T 723294
This standard specifies the method for determining the A-weighted sound pressure level of packaging machinery products and calculating the A-weighted sound power level. This standard applies to packaging machinery products that generate steady-state noise that radiates wide frontal bands, narrow frontal bands, discrete frequencies and their combinations. In addition to burst sounds with a repetition rate of less than five per second, it is also applicable to packaging machinery products that generate non-steady-state noise. This method is particularly suitable for on-site measurement, and does not require the sound source to be moved into a dedicated acoustic environment. There is no limit on the volume of the product to be measured. For products with extra-large sizes, the part with the main noise source is selected for measurement. The data measured by the method specified in this standard can be used for comparison of products with similar sizes and types: a.
b. To assess the A-weighted sound power level of a product, 2 Reference standards
GB 3102.7
Acoustic quantities and units
GB 3768
GB3785
GB3947
GB4215
JJG176
Determination of sound power level of noise source - simple method Electrical and acoustic performance and test method of sound level meter Acoustic terminology
Determination of sound power level of noise of metal cutting machine tools Trial verification procedure for sound pressure level calibrator
3 Measurement items and measurement errors
3.1 Measurement items
According to the measurement position on the measurement surface specified in this standard, the A-weighted sound pressure level is measured by a microphone and a sound pressure meter. 3.2 Determination of required items
Convert the A-weighted sound pressure level into the A-weighted sound power level. 3.3 Measurement error
For packaging products with uniform radiation spectrum density, the standard deviation shall not exceed 4dB; for products with discrete radiation frequencies, the standard deviation shall not exceed 5dB; when comparing products of the same type and specification in the same test environment, the standard deviation shall be less than 3dB. 4 Acoustic test environment
4.1 Requirements for test environment
The test environments required by this standard are: a. a room with an approximately free field above a reflective surface; b. a flat outdoor venue with a hard reflective surface; and a common room that meets the requirements through test environment identification. Approved by the Ministry of Machinery Industry on July 18, 1994
Implementation on July 1, 1995
JB/T 7232-94
4.2 The limit value for determining whether the test environment meets the test requirements is A/S1 (A is the sound absorption of the room and S is the measurement surface area). Or the environmental correction value K\u22647.
Note: The determination of sound absorption A refers to the relevant provisions of Appendix A of GB3768. 4.3 When measuring noise, reflective objects or walls should be avoided near the measured product, especially between the measuring point and the measured product (measurement distance). There should be no blocking objects or sound-absorbing materials, etc. 4.4 Background noise and its correction value K
When measuring noise, the difference between the noise A-weighted sound pressure level of the measured product during operation and the background noise A-weighted sound pressure level of each measuring point should be no less than 3dB, otherwise the measurement is invalid.
See Table 1 for the background noise correction value.
Table 1
Difference between the sound pressure level of noise A of the tested product when it is working
and the sound pressure level of background noise A
4.5 Wind speed
Background noise correction value
Noise correction value K,
When measuring outdoors, the wind speed should be less than 6m/s (equivalent to level 4 wind). And a wind hood should be used. 4.6 Temperature and air pressure
When the correction value caused by the temperature of the test environment: deviates from 20C and the air pressure p. is higher by 100kPa and is equal to or greater than 0.5dB, correction should be made. The correction value K, is calculated in units of 0.5dB, and the calculation formula is as follows; K,=10lg0
Wherein, K,
Temperature and air pressure correction value, dB(A):
t-temperature of the test environment, C:
pn---air pressure of the test environment, kPa.
5 Measuring instruments
5.1 Overview
100 N273 + t
The test instrument shall be a sound level meter of type 1 or above specified in GB3785. Other measuring instruments with the same accuracy as this type of sound level meter may also be used. It is best to use an extension cable or extension rod between the sound level meter and the microphone. 5.2 Calibration
The test instrument shall be calibrated regularly. The entire test system including the transmitter and cable shall be calibrated in accordance with relevant regulations before and after each test to ensure the accuracy of the test instrument.
6 Product installation and working conditions
6.1 Product installation
JB/T7232-94
The packaging machinery product to be tested shall be installed in accordance with the requirements specified in the product manual, and installed at one or more positions on the reflecting plane, and can be used normally.
6.2 Auxiliary equipment
The auxiliary equipment closely related to the normal operation of the tested product should also be kept in working condition during the test, and the auxiliary equipment should not radiate obvious noise energy in the test environment. If it has a significant impact on the test results, it should be placed outside the test environment or isolated measures should be adopted to reduce its impact.
6.3 Product test status
During the measurement, the drum test product should be in the positive belt working state. The following working states can also be selected: a. The maximum noise state that can be generated under no-load conditions; b. The maximum noise state generated under specified load conditions. 7 Measurement method
7.1 Reference body
The reference body is an imaginary minimum rectangular hexahedron that just envelops the sound source (the tested product) and whose bottom surface coincides with the reflection surface. When determining the size of the reference body, the protruding part of the sound source can be ignored as long as it is not the main radiator of sound energy. For safety reasons, the reference body can be selected to be large enough to include the dangerous working point. 7.2 Measurement surface
There are two types of measurement surfaces, one is a hemispherical measurement surface and the other is a rectangular hexahedron measurement surface. 7.2.1 Hemispherical measurement surface
Hemispherical measurement surface is mainly used for products with smaller volume and limited sound source. The maximum size of the reference body is not more than 1m. The ratio of the radius of the hemispherical measurement surface to the maximum size of the reference body should be not less than 2. Generally, hemispherical measurement surface should be used first. 7.2.1.1 Measurement point position of hemispherical measurement surface The position of the microphone is located on an imaginary hemispherical surface with a radius of r and an area of \u200b\u200bS=2rr. The hemispherical surface envelops the sound source and the bottom surface is on the reflection plane. The measurement distance refers to the distance from the projection point of the geometric center of the sound source-reference body on the reflection plane to the measurement surface. The center of the hemisphere should coincide with the projection point of the geometric center of the reference body on the reflection plane and serve as the origin of the coordinate system. The microphones are arranged on the hemispherical measurement surface. The number of measuring points and their coordinates are shown in Table 2 and Figure 1. The position of the measuring point relative to the measured sound source (the position of the X and Y coordinate axes) should be determined by prediction. The noise of the sound source is measured on the circular path formed by the rotation radius of 0.8r from the Z coordinate axis at a height of 0.6r (Z coordinate). Find the point (position) with the highest A-weighted sound pressure level. One of the four microphones shown in Figure 1 should coincide with this point. The X and Y axes of the coordinate system are not necessarily parallel to the side length of the reference body. If the sound source radiates an audible discrete rate, a large error will occur when measuring Lw at a height of 0.6r. In this case, the measuring point position (B coordinate) can be located on the hemispherical measurement surface just above the reflection plane. However, it can only be used when the ground is a hard reflective material, such as concrete and asphalt. The distance of the microphone above the ground cannot be greater than 0.05m. Its coordinate values \u200b\u200bare shown in Table 2. Table 2 Coordinates of measuring points on the hemispherical measurement surface
Measuring point
0. 0
Measuring point with height of\0.6r
0. 0
0. 8
0. 6
0. 6
0. 6
-1. 0
Measuring point on reflecting plane
0. 0
-1.0
<0.05m
<0.05m
<0.05m
<0.05 m
Measurement table
JB/T7232-94
Benchmark surface review
OBasic measuring point
Figure 1 Location of measuring point on hemispherical measuring surface
7.2.1.2 Measurement of hemispherical measurement surface
Measure the A-weighted sound pressure level at the four basic measurement point positions shown in Figure 1, and refer to Table 1 to correct the background noise for the values \u200b\u200bof the four measurement points. Finally, calculate the average A-weighted sound pressure level and A-weighted sound power level of the measurement surface according to Chapter 8. 7.2.2 Rectangular hexahedron measurement surface
For longer and higher packaging machinery products or when measurements can only be made at a position close to the product, a rectangular hexahedron measurement base surface can be used. The microphones are distributed on the surface of an imaginary rectangular hexahedron that is parallel to the surfaces of the reference body and the distance between the corresponding surfaces is d. The distance is usually 1m, and the minimum distance should not be less than 0.25m. Measurement point positions on the rectangular hexahedron measurement surface: When a rectangular hexahedron measurement surface is used, the number of measurement points and their arrangement are divided into three cases in this standard. When the ratio of the length dimension to the height dimension of the reference body is less than 2 and the horizontal dimension does not exceed 1m, the measurement surface and the distribution of the measuring points are shown in a.
Figure 2.
The 1st to 4th basic measuring points are distributed on the height of the sheet. The center position of the top surface of the measuring surface is the 5th basic measuring point. In addition, the highest point of the A-weighted sound pressure level along the measuring surface is found on the height as the 6th basic measuring point. b. When the ratio of the length dimension to the height dimension of the reference body is greater than 2, the horizontal dimension exceeds 1m, and the difference between the maximum sound pressure level and the minimum sound pressure level of the sound source exceeds 5dB, in addition to the six basic measuring points in a, there should be four additional measuring points. As shown in Figure 3. The additional measuring points are distributed at the four corners of the horizontal rectangle at the height h, namely the 7th, 8th, 9th, and 10th additional measuring points. For packaging products with long horizontal dimensions (over 2.5tm), the distribution of measuring points should include additional intermediate measuring points in addition to the 10 measuring points specified in Figure 3. When the measuring distance d is less than or equal to 1m, the distance between measuring points should be less than or equal to 2m; when the measuring distance d is greater than 1m, the distance between measuring points should be less than or equal to (2d)m, see Figure 3. Figure 2
JB/T 7232--94
Small sound source range
*
Entire body
Measurement point position on the receiving surface
Figure 3 Measurement point position on the measurement surface of a large sound source rectangular hexahedron Reference surface
Special surface
Standard surface
Basic measurement point
Base surface
Measurement surface
th15m
Reference surface
Sub-surface
Base This measuring point
Additional measuring point
XAdditional intermediate measuring point
For a packaging machinery production line composed of multiple single machines connected by a transmission device, the distribution of the reference body, measurement surface and measurement points are determined according to the specific situation of the measured product and the purpose of measuring noise. When each single machine in the production line can work independently and the purpose of measuring noise is to evaluate the noise level of each working host, the reference body should select each working host as the object, that is, the working host is the main noise source. The noise impact of the transmission device on the host is very small and can generally be ignored. The measurement surface can be determined according to the method described above. When the working hosts in the production line are interlocked, and the purpose of measuring noise is to evaluate the noise level of the entire production line, the reference body and measurement surface should be based on the production line. The distribution of measurement points in the host part can be determined according to the method described above. Only two measurement points are selected in the transmission device part, that is, find the two points with the maximum and minimum A-weighted sound pressure levels along the measurement surface in height. The height should be calculated based on the height H of the transmission device. See Figure 4.
Surface of reference body
Measurement surface
6.15
Machine
Transmission capacity
Maximum point of sound pressure level
Minimum point of sound pressure level
Figure 4 Measurement point of transmission device
Host
Surface of reference body
Measurement attenuation surface
O Measurement point
For large packaging machinery products whose ratio of horizontal length dimension to height dimension is less than 1 and whose height exceeds 2.5m, measurement points shall be arranged at two heights h and h=\uff08H+d)/2. Take the 1st to 4th basic measurement points in Figure 2, plus the measurement points at h, height A is the point with the largest A-weighted sound pressure level); h, = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus h: the point with the largest A-weighted sound pressure level in height, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11 points. For the production line using high-altitude digital hanging conveying device, considering that its noise is relatively low, the reference body and the measuring surface are difficult to determine, and the effect on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can select three points, namely the point with the largest and smallest sound pressure level, and then select any point. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.25m. Measuring point positions of rectangular hexahedron measuring surface: When a rectangular hexahedron measuring surface is used, the number of measuring points and their arrangement are divided into three cases in this standard. When the ratio of the length dimension to the height dimension of the reference body is less than 2 and the horizontal dimension does not exceed 1m, the measuring surface and the distribution of measuring points are shown in a.
Figure 2.
The 1st to 4th basic measuring points are distributed on the height of the sheet. The center position of the top surface of the measuring surface is the 5th basic measuring point. In addition, the highest point of the A-weighted sound pressure level is found along the measuring surface on the height as the 6th basic measuring point. b. When the ratio of the length dimension to the height dimension of the reference body is greater than 2, the horizontal dimension exceeds 1m, and the difference between the maximum sound pressure level and the minimum sound pressure level of the sound source exceeds 5dB, in addition to the six basic measuring points in a, there should be four additional measuring points. As shown in Figure 3. The additional measuring points are distributed at the four corners of the horizontal rectangle at the height of h, namely the 7th, 8th, 9th, and 10th additional measuring points. For packaging products with long horizontal dimensions (over 2.5tm), the distribution of measuring points should include additional intermediate measuring points in addition to the 10 measuring points specified in Figure 3. When the measuring distance d is less than or equal to 1m, the distance between measuring points should be less than or equal to 2m; when the measuring distance d is greater than 1m, the distance between measuring points should be less than or equal to (2d)m, see Figure 3. Figure 2
JB/T 7232--94
Small sound source range
*
Entire body
Measurement point position on the receiving surface
Figure 3 Measurement point position on the measurement surface of a large sound source rectangular hexahedron Reference surface
Special surface
Standard surface
Basic measurement point
Base surface
Measurement surface
th15m
Reference surface
Sub-surface
Base This measuring point
Additional measuring point
XAdditional intermediate measuring point
For a packaging machinery production line composed of multiple single machines connected by a transmission device, the distribution of the reference body, measurement surface and measurement points are determined according to the specific situation of the measured product and the purpose of measuring noise. When each single machine in the production line can work independently and the purpose of measuring noise is to evaluate the noise level of each working host, the reference body should select each working host as the object, that is, the working host is the main noise source. The noise impact of the transmission device on the host is very small and can generally be ignored. The measurement surface can be determined according to the method described above. When the working hosts in the production line are interlocked, and the purpose of measuring noise is to evaluate the noise level of the entire production line, the reference body and measurement surface should be based on the production line. The distribution of measurement points in the host part can be determined according to the method described above. Only two measurement points are selected in the transmission device part, that is, find the two points with the maximum and minimum A-weighted sound pressure levels along the measurement surface in height. The height should be calculated based on the height H of the transmission device. See Figure 4.
Surface of reference body
Measurement surface
6.15
Machine
Transmission capacity
Maximum point of sound pressure level
Minimum point of sound pressure level
Figure 4 Measurement point of transmission device
Host
Surface of reference body
Measurement attenuation surface
O Measurement point
For large packaging machinery products whose ratio of horizontal length dimension to height dimension is less than 1 and whose height exceeds 2.5m, measurement points shall be arranged at two heights h and h=\uff08H+d)/2. Take the 1st to 4th basic measurement points in Figure 2, plus the measurement points at h, height A is the point with the largest A-weighted sound pressure level); h, = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus h: the point with the largest A-weighted sound pressure level in height, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11 points. For the production line using high-altitude digital hanging conveying device, considering that its noise is relatively low, the reference body and the measuring surface are difficult to determine, and the effect on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can select three points, namely the point with the largest and smallest sound pressure level, and then select any point. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.25m. Measuring point positions of rectangular hexahedron measuring surface: When a rectangular hexahedron measuring surface is used, the number of measuring points and their arrangement are divided into three cases in this standard. When the ratio of the length dimension to the height dimension of the reference body is less than 2 and the horizontal dimension does not exceed 1m, the measuring surface and the distribution of measuring points are shown in a.
Figure 2.
The 1st to 4th basic measuring points are distributed on the height of the sheet. The center position of the top surface of the measuring surface is the 5th basic measuring point. In addition, the highest point of the A-weighted sound pressure level is found along the measuring surface on the height as the 6th basic measuring point. b. When the ratio of the length dimension to the height dimension of the reference body is greater than 2, the horizontal dimension exceeds 1m, and the difference between the maximum sound pressure level and the minimum sound pressure level of the sound source exceeds 5dB, in addition to the six basic measuring points in a, there should be four additional measuring points. As shown in Figure 3. The additional measuring points are distributed at the four corners of the horizontal rectangle at the height of h, namely the 7th, 8th, 9th, and 10th additional measuring points. For packaging products with long horizontal dimensions (over 2.5tm), the distribution of measuring points should include additional intermediate measuring points in addition to the 10 measuring points specified in Figure 3. When the measuring distance d is less than or equal to 1m, the distance between measuring points should be less than or equal to 2m; when the measuring distance d is greater than 1m, the distance between measuring points should be less than or equal to (2d)m, see Figure 3. Figure 2
JB/T 7232--94
Small sound source range
*
Entire body
Measurement point position on the receiving surface
Figure 3 Measurement point position on the measurement surface of a large sound source rectangular hexahedron Reference surface
Special surface
Standard surface
Basic measurement point
Base surface
Measurement surface
th15m
Reference surface
Sub-surface
Base This measuring point
Additional measuring point
XAdditional intermediate measuring point
For a packaging machinery production line composed of multiple single machines connected by a transmission device, the distribution of the reference body, measurement surface and measurement points are determined according to the specific situation of the measured product and the purpose of measuring noise. When each single machine in the production line can work independently and the purpose of measuring noise is to evaluate the noise level of each working host, the reference body should select each working host as the object, that is, the working host is the main noise source. The noise impact of the transmission device on the host is very small and can generally be ignored. The measurement surface can be determined according to the method described above. When the working hosts in the production line are interlocked, and the purpose of measuring noise is to evaluate the noise level of the entire production line, the reference body and measurement surface should be based on the production line. The distribution of measurement points in the host part can be determined according to the method described above. Only two measurement points are selected in the transmission device part, that is, find the two points with the maximum and minimum A-weighted sound pressure levels along the measurement surface in height. The height should be calculated based on the height H of the transmission device. See Figure 4.
Surface of reference body
Measurement surface
6.15
Machine
Transmission capacity
Maximum point of sound pressure level
Minimum point of sound pressure level
Figure 4 Measurement point of transmission device
Host
Surface of reference body
Measurement attenuation surface
O Measurement point
For large packaging machinery products whose ratio of horizontal length dimension to height dimension is less than 1 and whose height exceeds 2.5m, measurement points shall be arranged at two heights h and h=\uff08H+d)/2. Take the 1st to 4th basic measurement points in Figure 2, plus the measurement points at h, height A is the point with the largest A-weighted sound pressure level); h, = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus h: the point with the largest A-weighted sound pressure level in height, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11 points. For the production line using high-altitude digital hanging conveying device, considering that its noise is relatively low, the reference body and the measuring surface are difficult to determine, and the effect on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can select three points, namely the point with the largest and smallest sound pressure level, and then select any point. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.The distance between measuring points should be less than or equal to (2d)m, see Figure 3. Figure 2
JB/T 7232--94
Small sound source range
*
Entire body
Measurement point position on the receiving surface
Figure 3 Measurement point position on the measurement surface of a large sound source rectangular hexahedron Reference surface
Precision surface
Standard surface
Basic measuring point
Base difficult surface
Measurement surface
th15m
Reference surface
Sub-surface
Base This measuring point
Additional measuring point
XAdditional intermediate measuring point
For a packaging machinery production line composed of multiple single machines connected by a transmission device, the distribution of the reference body, measurement surface and measurement points are determined according to the specific situation of the measured product and the purpose of measuring noise. When each single machine in the production line can work independently and the purpose of measuring noise is to evaluate the noise level of each working host, the reference body should select each working host as the object, that is, the working host is the main noise source. The noise impact of the transmission device on the host is very small and can generally be ignored. The measurement surface can be determined according to the method described above. When the working hosts in the production line are interlocked, and the purpose of measuring noise is to evaluate the noise level of the entire production line, the reference body and measurement surface should be based on the production line. The distribution of measurement points in the host part can be determined according to the method described above. Only two measurement points are selected in the transmission device part, that is, find the two points with the maximum and minimum A-weighted sound pressure levels along the measurement surface in height. The height should be calculated based on the height H of the transmission device. See Figure 4.
Surface of reference body
Measurement surface
6.15
Machine
Transmission capacity
Maximum point of sound pressure level
Minimum point of sound pressure level
Figure 4 Measurement point of transmission device
Host
Surface of reference body
Measurement attenuation surface
O Measurement point
For large packaging machinery products whose ratio of horizontal length dimension to height dimension is less than 1 and whose height exceeds 2.5m, measurement points shall be arranged at two heights h and h=\uff08H+d)/2. Take the 1st to 4th basic measurement points in Figure 2, plus the measurement points at h, height A is the point with the largest A-weighted sound pressure level); h, = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus h: the point with the largest A-weighted sound pressure level in height, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11 points. For the production line using high-altitude digital hanging conveying device, considering that its noise is relatively low, the reference body and the measuring surface are difficult to determine, and the effect on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can select three points, namely the point with the largest and smallest sound pressure level, and then select any point. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.The distance between measuring points should be less than or equal to (2d)m, see Figure 3. Figure 2
JB/T 7232--94
Small sound source range
*
Entire body
Measurement point position on the receiving surface
Figure 3 Measurement point position on the measurement surface of a large sound source rectangular hexahedron Reference surface
Precision surface
Standard surface
Basic measuring point
Base difficult surface
Measurement surface
th15m
Reference surface
Sub-surface
Base This measuring point
Additional measuring point
XAdditional intermediate measuring point
For a packaging machinery production line composed of multiple single machines connected by a transmission device, the distribution of the reference body, measurement surface and measurement points are determined according to the specific situation of the measured product and the purpose of measuring noise. When each single machine in the production line can work independently and the purpose of measuring noise is to evaluate the noise level of each working host, the reference body should select each working host as the object, that is, the working host is the main noise source. The noise impact of the transmission device on the host is very small and can generally be ignored. The measurement surface can be determined according to the method described above. When the working hosts in the production line are interlocked, and the purpose of measuring noise is to evaluate the noise level of the entire production line, the reference body and measurement surface should be based on the production line. The distribution of measurement points in the host part can be determined according to the method described above. Only two measurement points are selected in the transmission device part, that is, find the two points with the maximum and minimum A-weighted sound pressure levels along the measurement surface in height. The height should be calculated based on the height H of the transmission device. See Figure 4.
Surface of reference body
Measurement surface
6.15
Machinewww.bzxz.net
Transmission capacity
Maximum point of sound pressure level
Minimum point of sound pressure level
Figure 4 Measurement point of transmission device
Host
Surface of reference body
Measurement attenuation surface
O Measurement point
For large packaging machinery products whose ratio of horizontal length dimension to height dimension is less than 1 and whose height exceeds 2.5m, measurement points shall be arranged at two heights h and h=\uff08H+d)/2. Take the 1st to 4th basic measurement points in Figure 2, plus the measurement points at h, height A is the point with the largest A-weighted sound pressure level); h, = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus h: the point with the largest A-weighted sound pressure level in height, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11 points. For the production line using high-altitude digital hanging conveying device, considering that its noise is relatively low, the reference body and the measuring surface are difficult to determine, and the effect on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can select three points, namely the point with the largest and smallest sound pressure level, and then select any point. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.Take the 1st to 4th basic measuring points in Figure 2, plus the point with the largest A-weighted sound pressure level at height h); h = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus the point with the largest A-weighted sound pressure level at height h, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11. For production lines using high-altitude digital hanging conveying devices, considering that their noise is relatively low, the reference body and the measuring surface are difficult to determine, and the impact on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can be selected from three points, namely the points with the largest and smallest sound pressure levels, and then any other points. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.Take the 1st to 4th basic measuring points in Figure 2, plus the point with the largest A-weighted sound pressure level at height h); h = H + d, take the 11th to 14th additional measuring points in Figure 3 (i.e. the measuring points on the four corners) plus the point with the largest A-weighted sound pressure level at height h, and there is also the measuring point at the center of the measuring surface, so the number of measuring points is at least 11. For production lines using high-altitude digital hanging conveying devices, considering that their noise is relatively low, the reference body and the measuring surface are difficult to determine, and the impact on the noise level of the production line is not significant, so it can be ignored. If there are special requirements, the measuring points of the hanging conveying device can be selected from three points, namely the points with the largest and smallest sound pressure levels, and then any other points. The measuring distance d is usually 1m, and the measuring surface can be approximately converted according to its unfolded and straightened state. Calculation of the average sound pressure level and sound power level of the measuring surface 8
8.1 The average sound pressure level Z of the measuring surface is calculated using formula (2): =10lg
C10\u00b01(Lr-K))
Wherein:
-average sound pressure level of the measuring surface, dB (reference value is 20uPa); Lg\u2014sound pressure level of the ith measuring point, dB (reference value is 20\u03bcPa); K\u2014background noise correction value of the /th measuring point.dB; N\u2014total number of measuring points.
Note: When the variation range of L value does not exceed 5dB, the arithmetic mean value can be used, and the calculation error is not greater than 0.6dB,6
8.2 Calculation of sound power level Lw
The sound power level Lw is calculated by formula (3):
Where: L
JB/T7232-94
L, = (Z, K,-K,) + 10lg(
Sound power level, dB (reference value is 1Pw); average sound pressure level of the measuring surface, dB (reference value is 20\u03bcPa); environmental correction value, dB:
K,\u2014\u2014temperature and air pressure correction value, dB
S.-1 m*;
S---measurement surface area, m. Hemispherical measurement surface area S-2mr, rectangular measurement surface area S=4(ab+bc+cu); a=(I,/2)+d;
b(/2)+d
c=+d;
1, 2, t,--reference body length, width, height, m; d--measurement distance, m
The determination of environmental correction value K, can refer to Appendix A of GB4215, and the calculation of directivity index can refer to Appendix B of GB4215. 9 Contents of test report
9.1 Test report The following should be stated:
Name, type, model, specification, serial number, production date (year, month) and manufacturer name of the product under test; a.
b. Installation status of the product under test:
Working status of the product under test.
9.2 Description of the test environment
Draw the size of the test environment and the installation position of the product under test, as well as the size and shape of the reflective objects around the product under test in proportion. Explain the properties of materials such as the ground, walls, and ceiling. 9.3Draw a diagram of the measurement surface and measurement point layout. 9.4If measuring outdoors, draw the location of the product under test. When drawing a schematic diagram, the distance to other objects should be marked to illustrate the measurement environment, reflective surface conditions, wind speed, weather, etc.
9.5 The name, model, manufacturer and calibration method of the instruments in the measurement system, and the time and department of the acoustic calibrator calibration. 9.6 Contents of the measurement data recording:
Measurement distance and measurement surface area S;
Background noise sound pressure level and its correction value, temperature and air pressure and its correction value measured at each measurement point; measurement data and calculation results of environmental correction value A-weighted sound pressure level at each measurement point;
Calculated average sound pressure of the measurement surface Level: Calculated A-weighted sound pressure level.
9.7 Subjective impression of the noise of the tested product: description of pure tone, pulse sound, noise, etc. 9.8 Test unit, time, place, and test participants. Draft
Additional notes:
JB/T723294
This standard is proposed and managed by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Machinery Standardization Research Institute of the Ministry of Machinery Industry and the Packaging Machinery Branch of the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Qu Minxiang, Wu Ruiping, Sun Chuan'en, Song Baozhong, and Zhou Shuangxi.
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