JB/T 8106-1999 The national standard GB 7772-87 "Measurement Method of Variable Volume Vacuum Pump Noise" was adjusted to the industry standard JB/T 8106-95 "Measurement Method of Variable Volume Vacuum Pump Noise" in 1995. This standard is a revision of it. Only editorial changes were made during the revision, and the main technical content remained unchanged. This standard non-equivalently adopts the international standard ISO 3744:1981 "Acoustics - Determination of Sound Power Level of Noise Sources - Engineering Method for Free Sound Field Conditions Above a Reflecting Plane". This standard specifies the measurement method of volume vacuum pump noise. This standard is applicable to the measurement of the sound power level of volume vacuum pump noise with an ultimate pressure of less than 100Pa and the ability to exhaust directly into the atmosphere. This standard was first issued in 1987. JB/T 8106-1999 Volume Vacuum Pump Noise Measurement Method JB/T8106-1999 Standard Download Decompression Password: www.bzxz.net

1Cs 25.160
Machinery Industry Standard of the People's Republic of China
JB/T8106—1999
Positive displacement vacuum pumps
Methuds of measurement for noise emitted by positive--displacement vacuum pumps1999-07-12Published
National Bureau of Machinery Industry
2000-01-01Implementation
JE/T8106—1999
National Standard GB77728 "Variable Volume Noise Measurement Method" was adopted as the industry standard JB/T81G69
Variable Volume Vacuum Pump Noise Measurement Method" in 1995. This standard is a revision of the original standard. During the revision, the original standard was revised and the main technical content was not changed.
This standard adopts the international standard IS03744:1981 "Acoustics - Determination of power level of noise source - A method for the condition of self-excitation sound field on a reflecting plane" in a non-equivalent manner.
This standard replaces JB8106-95 from the date of implementation. Appendix A of this standard is a standard appendix.
Appendix B of this standard is a reminder appendix.
This standard is produced by the National Vacuum Technology Standardization Technical Committee and is under the jurisdiction of the Shenhe Vacuum Technology Research Institute. The main drafters of this standard are Li Yuying and Li Chunying. The first release of the standard in 19th century
Mechanical Industry Standard of the People's Republic of China
Positive displacement vacuum pump
Noise measurement method
Methuds uf mehsaremeni for notye cmittrdbypositivedisplacementvacuum puraps does not specify the method for measuring the maximum noise point of the vacuum recording. IB/T8106—1999
neq1so3744:1981
8106-95
This standard is applicable to the measurement of the noise level of the air system (hereinafter referred to as the pump) with the ultimate pressure lower than 100Pa and which can directly discharge the air into the atmosphere.
2 Cited standards
The provisions contained in the following standards shall be reduced to technical standards by citing them in this standard. When this standard is released, the versions shown are valid. All standards will be verified. When using the standards, the latest versions of the following standards should be discussed: GT3785-1983 Performance and test methods of electrical components by grade JH785[-15] 1/ and 1.3 times frequency filtering for sound and vibration analysis JJO 176- 1995
JIG188-1990
Verification procedure for sound calibrators
Product grade meter verification procedure
3 Measurement items and measurement errors
3. Measurement items The main measurement items are Appendix A sound power level of the meter. In the automatic sound field or semi-automatic sound field, the frequency-driven frequency level or other weighted power level can be selected according to the needs.
3.2 Measurement tolerance
When the measurement environment complies with Appendix A (standard appendix), for the recording of the frequency of the emission of 10010000Hz and its spectral density, the standard deviation of the measured A-weighted sound power level shall not be greater than 2B; the standard deviation of the measured power level of the 11 times explosion band or 13 times the rated band shall not be greater than the values ​​listed in the table,
The error of the power level of the low frequency band center weighted car
250-50m
[/3 times the frequency band center weighted rate
2(0-63
|AUF-5CKK
63--1CH
Juice: The standard deviation of the frequency range of the following frequency items is about dB. Approved by the National Bureau of Machinery Industry [999-07-12]. Standard deviation. 000-01-01 Implementation. Acoustic measurement environment. 1. The measurement environment required by this standard is: a) a self-sound field laboratory with a reflecting surface. b) a hard and flat outdoor place. c) a room that meets the requirements of Appendix A. JB/T80 6-1999
When the actual test environment is close to the ideal state, the ambient pressure value shall be determined according to the value given in Appendix A: 4.2 Back noise
The difference between the A-band sound pressure level of the residual radiation channel and the back noise sound pressure level obtained at the corresponding measuring point shall be less than 1D! : When the difference between the two is less than 6-[UPa, the correction shall be made according to Table 2; if the difference is less than 6B, the correction shall be invalid, and the noise reduction stop position shall be the difference between the required source pressure level and the medium pressure level in the membrane in Table 3
4.3 Test
The test is invalid| |tt||When measuring leakage outdoors, a wind hood should be used. When the wind speed is greater than 6m/s (equivalent to level 4 wind), the measurement should be stopped. 5. Measuring instruments
5. Selection and requirements
The sound level meter should be of type 1 or type 2 specified in ASTM D1983, as well as other measuring instruments with equivalent accuracy. The sound level meter should be connected to other measuring instruments and microphones using an extension rod or body rod. For spectrum analysis, a 1/3 pre-precision filter should be used that meets the requirements of ASTM D19861. 5.2 Calibration
To verify the accuracy of the measuring instrument. Before and after the test panel is turned, a sound level calibrator with an accuracy of 0.5 is required. The entire test panel system (including the wire) is calibrated at multiple frequencies. The vehicle-level calibrator can be used as a remote generator, and 11G76 is calibrated regularly. Other test instruments should also be calibrated according to the G regulations. 6 Pump installation and working conditions
6.1 Installation position and requirements of the pump
The test piece should be placed at the geometric center of the ground in the test site. It is not fixed on the foundation, or placed on a non-returnable surface. When the object is tested, a fixed installation can be used, and the test report should be submitted to the city society. 6.2 System requirements
During the test, the integrity of the system will be tested. 6.3 Technical requirements
3.1 The pump is disconnected from the test accumulator, the air intake is closed, and it is operated under the following conditions: a) The difference between the actual speed of the pump and the rated value should not be greater than ±3%: b) The type and number of the object fluid should meet the design requirements: JD/T8106-1999
The cooling water of the water-cooled pump should meet the design requirements: When testing the gas ballast pump, close the gas ballast time.
6.3.2 After the object is started, the span should be rotated at least 30mm. When the pump temperature is stable and the system limit pressure is reached through measurement, the system can be operated.
7 Noise measurement
7.1 Measurement surface and measurement point position
7.1.1 Noise body
A small rectangular hexahedron that envelops the measured object and ends on the reflection plane is used as the reference body. The measurement surface and measurement points are arranged based on: When determining the reference body, the protruding part of the source can be ignored unless it is the main radiator of sound energy. 7.1.2 Measurement surface and measurement point position
-Standard is to use a rectangular hexahedron with each face parallel to the reference as the measurement surface. The surface area of ​​the measurement is calculated by formula (1): S = d (ab + be + ca)
Formula: aF1,2 + d:
6-ty2 + d;
I, Lt, L, are the length and width of the reference body, respectively; d is the measurement range distance. This standard takes -I m. The coordinates of the measurement point position are as shown in Figure 1 and Table 3. 2
M. Measurement area: B-sample: Measurement point
Figure 1 Transmitter arrangement on short body
7.1.3 Reduction of avoidance points
JB/T1061999
Table 3 Coordinates of measuring points on the surface of rectangular large surface
When the noise is symmetrically radiated, the number of measuring points can be appropriately reduced, but it must be ensured that the reduction of measuring points has no effect on the calculated sound power level. 1B7. 2 Measurement
7.2.1 The transmitter used for the measuring panel should be directly facing the pump to be measured. When the pump radiates steady-state noise, the "slow" time weighting characteristic of the sound level meter can be used to measure point by point. When the fluctuation range of the sound level meter reading is less than ±3 f within the observation period, the sound level reading can be taken as its average value (the excessive or too small value that occurs by accident will not be considered). If necessary, the relevant frequency band can be measured. 7.2.2 For the frequency bands with A-weighted sound pressure level and center frequency above 2001Hz, the observation reading time shall be at least 109; for the frequency bands with center frequency below 160Hz, the observation reading time shall be at least 30:. 7.2.3 The test personnel shall stay away from the sound field as far as possible and keep at least 0.5m away from the sound transmitter. 7.2.4 Before or after the measurement, the above-mentioned measurement method is used. Calculate the average sound pressure level on the measuring surface
The A-weighted average sound pressure level on the measuring surface or the average sound pressure level in the band is calculated by formula (2):
= 101[10%-
Where,
is the A-weighted average sound pressure level on the measuring surface or the average sound pressure level in the band, dB (reference value is 20Pa): Lp;
is the A-weighted sound pressure level or the average sound pressure level in the band measured at the /th measuring point, dB (reference value is 20μPa); K is the average value of the sound pressure at the /th measuring point, B is the total number of measuring points.
When the L value changes by no more than 5dH, the arithmetic mean method can be used for calculation. The difference between the value and the value calculated by (2) is not more than 0.7dB. 8.2 Calculation of sound power level
8.2.14 Calculation of weighted power level or frequency-weighted sound power level using formula (3): Lzg+101g
Where: LA is the power level or band sound power level, d (reference value is 1W) (3
S - measurement surface area, mWww.bzxZ.net
JT8t06-1999
K, the environment will be positive, d (according to the method given in Appendix A to determine 3.2.2 A weighted sound power level synthesized from 171 octave band or 1 total octave band sound frequency level, see Appendix B (suggested Appendix) 9 Measurement report
The content of the measurement report should include:
a) The model, name, specifications and installation and operation status of the pump to be tested; b) The model and specifications of the noise meter used:
d) The location of the measuring point and the purpose:
e) The noise level calculated by the point data.
A1 General requirements
A1, reverse plane characteristics
JB/T 8106-1999
Appendix
(Standard sound resistance!
Measurement environment adjustment
The sound characteristics of the reflecting surface should be close to the perfect sound reflecting surface in the relevant frequency range. Flat water and moving surfaces can meet the requirements.
2 Reflection plane size
The reflecting plane should be larger than the projection of the measuring surface on the reflecting plane. As far as possible within the relevant frequency range, A2 absolute comparison method
In the test environment, place the standard source at the position of the pump under test, that is, use the substitution method. And use the same measurement method as the measured cabinet to measure its level. The sound power of the standard sound source is calculated according to the method specified in Chapter 1 under the condition of no spherical environment. The environmental correction value K is calculated using formula (A1):
K,= Ly-Lm
Where: L is the A-weighted or frequency-weighted sound power level of the standard sound source measured in the test environment using the same measuring surface as the test pump, dB [reference value 1pw);
the A-weighted or frequency-weighted sound power level calibrated by the standard sound source, dB (reference value 1pw) Lw
A3 contains the following requirements:
According to A2, when the environmental energy is determined in a given measurement environment, the measurement environment meets the requirements of this standard.
Ja/T8106—1999
(suggested appendix)
The A-weighted sound power is synthesized from the 1:1 adjacent band or 13 times band sound power level. The method of power level is to use 11 frequency sections or 1/3 frequency bands as the sound power level, and the weighted average sound level Lw is calculated according to the formula (B1). B1
Where: Lw—the first, 1/octave band or 1 octave band is used as the sound power level, B (according to the standard value 1pW uses the octave band, the power level is calculated, and the formula (B1) is given in Table B1, -7, B2
1 times the center source frequency
Use 1 times the center source frequency
Use 1 times the center source frequency
Use 1 times the center source frequency
Use Table 2 to calculate the sound power level, and the formula (B1) uses Table 2, m-21R3
Book frequency band center report frequency
I8/T$106-1999
Morning B2 (end)
1:3 octave band center explosion car
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