JJG 921-1996 Verification Procedure for Pollution Noise Vibrometers JJG921-1996 Standard download decompression password: www.bzxz.net
This procedure applies to the verification of pollution noise vibration meters (including noise vibration statistical analyzers and environmental vibration monitors) that are newly manufactured, in use, and after repair.

The National Metrology Verification Regulation of the People's Republic of China JIG921-1996
NoiseVibrationMelerfor
Measuring Environmental Pollution1996-11-18 Issued
1997～05-01 Implementation
National Technical Supervision Bureau Issued
JJG92I—1996
NoiseVibrationMelerfor
Verification Regulation of
NoisevibrationMeterfor
MeasuringEnvrionmentalPouutionJJG921—1996
This verification procedure was approved by the State Technical Supervision Bureau on November 18, 1996, and implemented on May 1, 1997
Responsible unit: National Vibration and Impact Meter Technical Committee Drafting unit: Beijing Institute of Metrology The drafting unit is responsible for interpreting the technical text of this procedure Main drafters of this procedure:
Sheng Minxue
Liu Weijin
Participating drafter!
Yang Xinyao
JJG 921 1996
(Beijing Institute of Metrology)
(Beijing Institute of Metrology)
(Analysis and Testing Center of Zhejiang University)
[Hangzhou Institute of Electronic Industry Mechanical and Electrical General Factory
Technical requirements
Selection conditions
Verification items and verification methods
Verification result processing and verification cycle
Appendix 1
Appendix 2
Appendix!
Calibration certificate (back) format
JJG921-1996
Calibration result notice (back) Greek style
Calibration record format
Calibration date of environmental noise vibration meter
Appendix 4
(2)
JIC921-1996
Calibration procedures for environmental noise vibration meter
This procedure is applicable to the calibration of environmental noise vibration meter (including noise vibration statistical analysis, environmental monitoring) newly manufactured, in use and after repair.
1 Overview
The environmental noise vibration meter is composed of a perturbation transmitter and a microphone, an amplifier with a specified frequency weighting, and a detector-average assigner. It is a multi-purpose portable measuring instrument, which can measure the A-level and pressure level of noise, and can measure the "whole body vertical" and "whole body water half" weighted vibration and non-weighted vibration velocity level of vibration.
2 Technical requirements
1 Technical requirements for public noise noise meter 1.1 Level measurement range
1.1.1 The reading accuracy of the sound level measurement unit under various test conditions is ±0.7 for type 11 and 1.0 for type 2. 1.1.2 The A-level measurement accuracy and allowable error of the sound level range (range controller) shall meet the requirements of Table 3 within the given level measurement range.
1.1.4 In the specified sound level case range, the linear allowable error of the sound level indication shall meet the requirements of Table 4. 1.1.5 The allowable error of the effective value detection shall meet the requirements of Table 5. 1.1.6 The response of the time meter's "fast" (F) and "slow" (S) characteristics to the screening sound signal card shall meet the requirements of Table 6: 1.1.? The lower limit of the sound level measurement range refers to the lower end of the measurement that is 5B higher than the equivalent noise level. 1.1.8 If the instrument can perform statistical calculations: its allowable error shall meet the requirements of Table 6. 1.2 Level measurement
Under reference conditions, the calibration uncertainty of the overall vibration level sensitivity is 5.% 1.2.1
1.2.2 Level measurement
The measurement of general public pollution vibration is expressed by the following formula: L, = 20 Ig
Wherein: actual acceleration, called
——test acceleration, 4G=10m/s.
1.2.3 Frequency range of vibration level measurement: 1-·Hz. The permissible error of vibration level response shall meet the requirements of Table 8. 1.2.4 Within the given vibration level measurement range, the permissible error of amplitude linearity of vibration level measurement is ±0.1, and 11.0 d3:2t
JJC 921—1UG
1.3 Sound level stability In the specified environment, after preheating for 15 minutes and working continuously for 1 hour, the sound level reading of the instrument shall change within the range of 1 ±0.3(1) and 2 ±0.5(2). Three verification conditions:
(including temperature
2 Room temperature: (20±5, relative humidity: 30%～30%)
3 Atmospheric pressure: 86.0~106.0 k1...
4 Mechanical vibration of air-conditioning element
5 Environmental noise level of the instrument under test 10 Certificate [2 Calibration month instrument
6 Calibration instrument can be, Table 1
Item
Product level competition number
Standard product
A stimulus meter weighted special equipment
User level
(Range controller)
Sine signal generator
Standard travel transmitter
Measurement receiver
Acoustic sensitive controller
When the sound
Smoke signal generator
Positive signal generator
Precision Bridge in-city equipment
Calibration method
Technical requirements
Function range: 0.3-20Hz
Frequency deviation: better than 0.2dB
Harmonic distortion: better than 0.1%
Frequency recording accuracy: better than 1%
Output voltage: 0.13-10V
Resonance accuracy: better than
Conversion rate range: 2Hz-20kH
Accuracy: better than 0.2 dB
Frequency: 250Hz to 1C00Hz
Accuracy: better than =(.3 dH
Field deviation: excellent ± 0.2
Same library 1
Color pool: DC-·10M
Trace point: (-131.1
Accuracy ratio = 0.01:R
Verification items
Re-measurement Indication continuity
R.M. value detection continuity
Time meter
Statistical meter function
Vibration level (reference sensitivity, frequency response, value shallowness)
JTG921
Table (;
Frequency signal generator
Precision attenuation
Narrow sounding signal
Effective time pressure device
Acquired sound signal generator
Shot space attenuator
rl: times current 4. Device
Precision attenuation full energy
Frequency Thai effect standard device
Certification device
Same as serial number 1
Technical requirements
Model: C-·10 MHz
Operation range: 131.1
Degree of delay: free: (1.051
Original wave frequency: 1:2,7kHz
Repetition rate: 0.1~1000Hz
Repetition rate accuracy: better than ±3%
Sustaining time: 1mg-1
Sustaining time accuracy: better than 10
Condensation range: uC.
Voltage standard:
Same number 4
Student number
Company number 1
Standard driving element
Charge: 1.-1mHz
Maximum environment: 1 0
Latent head accuracy: 5%
Ratio of vibration:
Vibration direction: vertical and horizontal
Positive signal generator
Periodic frequency range: same as number 1
Amplitude difference: same as number 3
Electrical wave loss point: same as number 1
Rapid accuracy: same as number 1
Output voltage: same as number
Verification test
Vibration level (refer to Bellington
meter, frequency response,
amplitude linear change)
Sound level qualitative test
Accuracy test
JJG 921—1996
Requirement 1()
Verification Instrument
True Effective Voltmeter
Technical Requirements
Frequency Range: Division,No. 5
Voltage accuracy: same as No. 5
Low-voltage standard device
Sine signal generator
Precision carbon meter
Digital voltmeter
Standard voltage meter (including electric micro-receiver) Frequency unevenness division: ±5%
Uncertainty: ±(.1d
Frequency range: 0.3Hz-1Hz||tt| |Verification device size: 3.Self-check
Same as serial number 1
Same as serial number 3
Accuracy: +0.5%
Frequency: DC: 1-10kH.
Verification items and verification methods
7.1 Under the specified test environment conditions, verify the generator by substitution method according to Figure 1
Perform the new standard||tt| |Figure! The sound level sensitivity test block is used to test the sensitivity of the noise level. The standard microphone is placed in the field. Its reference axis should be aligned with the reference axis of the sound source, and its diaphragm should face the sound source. The distance between them is 1m. The frequency signal generator is set to 1000Hz, and its output is adjusted to make the standard system indicate 94.0B. It is used as the reference sound pressure level, and the frequency and sound pressure level remain unchanged. Then the standard microphone is taken out. The standard noise vibration meter calibrated by the sound calibrator is used to replace the standard microphone, so that the sound receiving surface of the noise vibration meter is consistent with the receiving position of the standard microphone. The difference between the indication of the noise vibration meter and 94.0B can be used to determine the accuracy of the noise vibration meter's recording sensitivity. It should comply with the provisions of Section 4
1, 1.1 of the Civil Regulations. 9211996
7.2 The noise vibration meter of the test equipment with known radiation characteristics (including the cable) can also be calibrated directly by using the acoustic calibrator.
8 Sound level measurement A frequency weighted characteristic error verification R.1 As shown in Figure 1, the substitution method is adopted. In the free sound field, keep the sound pressure unchanged, connect two frequency points in the table, and read the indication of each frequency point of the noise vibration meter respectively. The rate of error should be in accordance with the provisions of Table 2. 2
Nominal frequency Tz
Hz
5012:
A frequency/Hx
31.5-3000bzxZ.net
20-13 500
On the film to be busy with two points
On the poison range of the instantaneous protection point
Main range of giant external network positive point
Main range of external shooting quality industry point
Peak effect
JJC:9211996
2Liu set general scattering washing has been red when the inspection company moved the design, the film potential rate only characteristic heart product power consumption The information is welcome to be revised.
Confirm the block diagram must be Figure 2,
under some confidence
the extinguisher
self-Yang Fei
Medical 2A design waiting block reduction
now some data
JJ:921--1596
level (although Cui sensor) initial indication value verification
standard installation some such as Zhou 2 new display.
9.1 Level (attenuator) Check
Correct the tube number and the device report 100H rate point, thank the card input, make the public report dynamic meter indicate the current linear range of 1 limit, then change the level of the public noise vibration meter to the first level, and at the same time adjust the attenuator to the lowest level, so that the cloud is still small, the level of the level and the difference between the attenuator and the level of the public noise control (total level of the total level), the value should be in line with the current calculation of 11.3 other provisions. 9.2 Linear verification
Public noise vibration business personnel level, input! Q0DHz is the correct number, adjust the instrument, make the pollution limit vibration meter as the position to be tested: every 11 levels, with precise honey attack reduction, the value of the calibration value should meet the requirements of this regulation 1.4: the effective detector special inspection is clear
standard adopts the old sudden mountain method, the calibration equipment is less than 3. Public and dynamic meter
speech sound
A meter network information
Read? First, use the frequency continuous 2000 real effective signal as the teaching, respectively input the true effective value of the ten-characteristic weighted meter and the inspected public noise vibration meter, record the A meter and the effective value of the characteristic meter, then use the rate of 2 plus H to continuously verify the string signal loss: adjust its amplitude, so that the A meter weighted or effective value of the record is achieved, at this time, the sound vibration meter should comply with the provisions of Article 1.1.5 of the vehicle regulations. The repetition rate before the sound is eliminated is 401, and its duration is 5.56 (peak number 3) 11 time 1 weighted material verification. See Figure 4 for the verification point diagram.
Zhengfa Zhongfa Three Departments
Multi-4 Fashion Meter Block Diagram
Public: It is necessary to test the characteristics of vibration level
JJG9211996
The generator outputs a 2012 continuous stop signal, the noise vibration meter is set to the "acceleration" gear, and the input signal is adjusted to make the noise vibration meter display 116c mountain t, the sound burst generator outputs a single sound signal of 0.5= duration, and the signal amplitude remains unchanged. The time characteristic of the noise alarm meter is set to the "fast" gear, "L" state, and the change of the indication value of the test shall comply with the provisions of Section 1.1.6 of this regulation.
Make the sound burst generator output a single sound burst signal of 4 duration, keep the signal value unchanged, and the time characteristic of the noise vibration meter is set to the "slow" gear. The change of the indication value during the verification shall comply with the provisions of Item 1.1.6 of this Regulation. 11.2 Verification of time characteristics of sound
The burst generator outputs a sinusoidal signal with a frequency of 2000H, and the duration of a single burst is U.2s and U.5s respectively. The noise vibration meter is set to the "A" level, and the scale is in the "fast" and "slow" positions of the time characteristics. Repeat the above steps. The result shall comply with the provisions of Item 1.1.6 of this Regulation. 12 Verification of the lower limit of wind measurement range
The equivalent electrical impedance replaces the sensor of the noise vibration meter, and the noise vibration meter is measured according to the equivalent noise level at each frequency weight of the noise vibration meter. The value of the equivalent noise level plus 5 is the lower limit of the measurement range of the noise vibration meter. 13 Statistical calculation function verification
Verification block diagram is shown in Figure 5,
Upstream signal generating part
Precision subtractor
Figure 5 Statistical calculation function diagram
Public noise vibration meter
Sine multiple signal generating group output 1 (15 stop signal, adjust the output amplitude, make the public noise vibration meter indicate 14B.
Public noise vibration meter is set to sample N,=60 times, sampling time interval is t=15% instrument sampling 1-- [Time, almost 190 seconds, the output of the generator is attenuated, the sample is -200, so according to the chemical 7 continuous results should meet the requirements of this regulation 1.1.1.1, 14 sound level stability verification
Verification method diagram see Tao:
Positive power generator
Diagram center by the handover run set method diagram
Public noise throat production vibration meter
After the public noise Lu vibration meter is turned on and preheated for 15 minutes, the low-noise generator inputs 20 (for vibration level) or 1 cent [H2 The noise vibration meter of the test equipment with known radiation characteristics can also be calibrated directly by using the acoustic calibrator.
8 Sound level measurement A Frequency weighted characteristic error verification R.1 As shown in Figure 1, the substitution method is adopted. In the free sound field, the sound pressure is kept constant. Two frequency points are changed in the table. The indications of each frequency point of the noise vibration meter are read respectively. The rate of change should be in accordance with the provisions of Table 2. 2
Nominal frequency Tz
Hz
5012:
A Frequency/Hx
31.5-3000
20-13 500
On the film to be busy with two points
On the poison range of the instantaneous protection point
Main range of giant external network positive point
Main range of external shooting quality industry point
Peak effect
JJC:9211996
2Liu set general scattering washing has been red when the inspection company moved the design, the film potential rate only characteristic heart product power consumption The information is welcome to be revised.
Confirm the block diagram must be Figure 2,
under some confidence
the extinguisher
self-Yang Fei
Medical 2A design waiting block reduction
now some data
JJ:921--1596
level (although Cui sensor) initial indication value verification
standard installation some such as Zhou 2 new display.
9.1 Level (attenuator) Check
Correct the tube number and the device report 100H rate point, thank the card input, make the public report dynamic meter indicate the current linear range of 1 limit, then change the level of the public noise vibration meter to the first level, and at the same time adjust the attenuator to the lowest level, so that the cloud is still small, the level of the level and the difference between the attenuator and the level of the public noise control (total level of the total level), the value should be in line with the current calculation of 11.3 other provisions. 9.2 Linear verification
Public noise vibration business personnel level, input! Q0DHz is the correct number, adjust the instrument, make the pollution limit vibration meter as the position to be tested: every 11 levels, with precise honey attack reduction, the value of the calibration value should meet the requirements of this regulation 1.4: the effective detector special inspection is clear
standard adopts the old sudden mountain method, the calibration equipment is less than 3. Public and dynamic meter
speech sound
A meter network information
Read? First, use the frequency continuous 2000 real effective signal as the teaching, respectively input the true effective value of the ten-characteristic weighted meter and the inspected public noise vibration meter, record the A meter and the effective value of the characteristic meter, then use the rate of 2 plus H to continuously verify the string signal loss: adjust its amplitude, so that the A meter weighted or effective value of the record is achieved, at this time, the sound vibration meter should comply with the provisions of Article 1.1.5 of the vehicle regulations. The repetition rate before the sound is eliminated is 401, and its duration is 5.56 (peak number 3) 11 time 1 weighted material verification. See Figure 4 for the verification point diagram.
Zhengfa Zhongfa Three Departments
Multi-4 Fashion Meter Block Diagram
Public: It is necessary to test the characteristics of vibration level
JJG9211996
The generator outputs a 2012 continuous stop signal, the noise vibration meter is set to the "acceleration" gear, and the input signal is adjusted to make the noise vibration meter display 116c mountain t, the sound burst generator outputs a single sound signal of 0.5= duration, and the signal amplitude remains unchanged. The time characteristic of the noise alarm meter is set to the "fast" gear, "L" state, and the change of the indication value of the test shall comply with the provisions of Section 1.1.6 of this regulation.
Make the sound burst generator output a single sound burst signal of 4 duration, keep the signal value unchanged, and the time characteristic of the noise vibration meter is set to the "slow" gear. The change of the indication value during the verification shall comply with the provisions of Item 1.1.6 of this Regulation. 11.2 Verification of time characteristics of sound
The burst generator outputs a sinusoidal signal with a frequency of 2000H, and the duration of a single burst is U.2s and U.5s respectively. The noise vibration meter is set to the "A" level, and the scale is in the "fast" and "slow" positions of the time characteristics. Repeat the above steps. The result shall comply with the provisions of Item 1.1.6 of this Regulation. 12 Verification of the lower limit of wind measurement range
The equivalent electrical impedance replaces the sensor of the noise vibration meter, and the noise vibration meter is measured according to the equivalent noise level at each frequency weight of the noise vibration meter. The value of the equivalent noise level plus 5 is the lower limit of the measurement range of the noise vibration meter. 13 Statistical calculation function verification
Verification block diagram is shown in Figure 5,
Upstream signal generating part
Precision subtractor
Figure 5 Statistical calculation function diagram
Public noise vibration meter
Sine multiple signal generating group output 1 (15 stop signal, adjust the output amplitude, make the public noise vibration meter indicate 14B.
Public noise vibration meter is set to sample N,=60 times, sampling time interval is t=15% instrument sampling 1-- [Time, almost 190 seconds, the output of the generator is attenuated, the sample is -200, so according to the chemical 7 continuous results should meet the requirements of this regulation 1.1.1.1, 14 sound level stability verification
Verification method diagram see Tao:
Positive power generator
Diagram center by the handover run set method diagram
Public noise throat production vibration meter
After the public noise Lu vibration meter is turned on and preheated for 15 minutes, the low-noise generator inputs 20 (for vibration level) or 1 cent [H2 The noise vibration meter of the test equipment with known radiation characteristics can also be calibrated directly by using the acoustic calibrator.
8 Sound level measurement A Frequency weighted characteristic error verification R.1 As shown in Figure 1, the substitution method is adopted. In the free sound field, the sound pressure is kept constant. Two frequency points are changed in the table. The indications of each frequency point of the noise vibration meter are read respectively. The rate of change should be in accordance with the provisions of Table 2. 2
Nominal frequency Tz
Hz
5012:
A Frequency/Hx
31.5-3000
20-13 500
On the film to be busy with two points
On the poison range of the instantaneous protection point
Main range of giant external network positive point
Main range of external shooting quality industry point
Peak effect
JJC:9211996
2Liu set general scattering washing has been red when the inspection company moved the design, the film potential rate only characteristic heart product power consumption The information is welcome to be revised.
Confirm the block diagram must be Figure 2,
under some confidence
the extinguisher
self-Yang Fei
Medical 2A design waiting block reduction
now some data
JJ:921--1596
level (although Cui sensor) initial indication value verification
standard installation some such as Zhou 2 new display.
9.1 Level (attenuator) Check
Correct the tube number and the device report 100H rate point, thank the card input, make the public report dynamic meter indicate the current linear range of 1 limit, then change the level of the public noise vibration meter to the first level, and at the same time adjust the attenuator to the lowest level, so that the cloud is still small, the level of the level and the difference between the attenuator and the level of the public noise control (total level of the total level), the value should be in line with the current calculation of 11.3 other provisions. 9.2 Linear verification
Public noise vibration business personnel level, input! Q0DHz is the correct number, adjust the instrument, make the pollution limit vibration meter as the position to be tested: every 11 levels, with precise honey attack reduction, the value of the calibration value should meet the requirements of this regulation 1.4: the effective detector special inspection is clear
standard adopts the old sudden mountain method, the calibration equipment is less than 3. Public and dynamic meter
speech sound
A meter network information
Read? First, use the frequency continuous 2000 real effective signal as the teaching, respectively input the true effective value of the ten-characteristic weighted meter and the inspected public noise vibration meter, record the A meter and the effective value of the characteristic meter, then use the rate of 2 plus H to continuously verify the string signal loss: adjust its amplitude, so that the A meter weighted or effective value of the record is achieved, at this time, the sound vibration meter should comply with the provisions of Article 1.1.5 of the vehicle regulations. The repetition rate before the sound is eliminated is 401, and its duration is 5.56 (peak number 3) 11 time 1 weighted material verification. See Figure 4 for the verification point diagram.
Zhengfa Zhongfa Three Departments
Multi-4 Fashion Meter Block Diagram
Public: It is necessary to test the characteristics of vibration level
JJG9211996
The generator outputs a 2012 continuous stop signal, the noise vibration meter is set to the "acceleration" gear, and the input signal is adjusted to make the noise vibration meter display 116c mountain t, the sound burst generator outputs a single sound signal of 0.5= duration, and the signal amplitude remains unchanged. The time characteristic of the noise alarm meter is set to the "fast" gear, "L" state, and the change of the indication value of the test shall comply with the provisions of Section 1.1.6 of this regulation.
Make the sound burst generator output a single sound burst signal of 4 duration, keep the signal value unchanged, and the time characteristic of the noise vibration meter is set to the "slow" gear. The change of the indication value during the verification shall comply with the provisions of Item 1.1.6 of this Regulation. 11.2 Verification of time characteristics of sound
The burst generator outputs a sinusoidal signal with a frequency of 2000H, and the duration of a single burst is U.2s and U.5s respectively. The noise vibration meter is set to the "A" level, and the scale is in the "fast" and "slow" positions of the time characteristics. Repeat the above steps. The result shall comply with the provisions of Item 1.1.6 of this Regulation. 12 Verification of the lower limit of wind measurement range
The equivalent electrical impedance replaces the sensor of the noise vibration meter, and the noise vibration meter is measured according to the equivalent noise level at each frequency weight of the noise vibration meter. The value of the equivalent noise level plus 5 is the lower limit of the measurement range of the noise vibration meter. 13 Statistical calculation function verification
Verification block diagram is shown in Figure 5,
Upstream signal generating part
Precision subtractor
Figure 5 Statistical calculation function diagram
Public noise vibration meter
Sine multiple signal generating group output 1 (15 stop signal, adjust the output amplitude, make the public noise vibration meter indicate 14B.
Public noise vibration meter is set to sample N,=60 times, sampling time interval is t=15% instrument sampling 1-- [Time, almost 190 seconds, the output of the generator is attenuated, the sample is -200, so according to the chemical 7 continuous results should meet the requirements of this regulation 1.1.1.1, 14 sound level stability verification
Verification method diagram see Tao:
Positive power generator
Diagram center by the handover run set method diagram
Public noise throat production vibration meter
After the public noise Lu vibration meter is turned on and preheated for 15 minutes, the low-noise generator inputs 20 (for vibration level) or 1 cent [H56 (peak value 3) 11 time 1 weighted material verification
Verification point diagram see Figure 4.
Zhengfa Zhongfa three parts
multi-4 fashion meter weighted special grab block diagram
public: must
11.1 vibration level time characteristic verification
JJG9211996
The generator outputs 2012 continuous stop string borrowing signal, the public noise Lu vibration meter is placed in the "acceleration" block, the input signal is adjusted, the public noise movement meter displays 116c mountain t, the sudden sound generator expands a single receiving sound signal of 0.5= duration, keeps the signal amplitude unchanged, the time characteristic of the public noise alarm meter is set to "fast" block, "L" state, and the change of the verification indication value shall comply with the provisions of Section 1.1.6 of this regulation.
Make the sound generator output a single burst sound signal of 4 duration, keep the signal value unchanged, and set the time characteristic of the noise vibration meter to "slow". The change of the indication value during the verification shall comply with the provisions of Item 1.1.6 of this Regulation. 11.2 Verification of sound time characteristic
The burst generator outputs a sinusoidal signal with a frequency of 2000H, and the duration of a single burst is U.2s and U.5s respectively. The noise vibration meter is set to "A" level, and the time characteristic is in the "fast" and "slow" positions. Repeat the above steps. The result shall comply with the provisions of Item 1.1.6 of this Regulation. 12 Verification of wind measurement range lower limit
The equivalent impedance replaces the sensor of the noise vibration meter, and the equivalent noise level at each frequency weight of the noise vibration meter is measured. The value of the equivalent noise level plus 5 is the measurement range lower limit of the noise vibration meter. 13 Statistical calculation function verification
Verification block diagram is shown in Figure 5,
Upstream signal generating part
Precision subtractor
Figure 5 Statistical calculation function diagram
Public noise vibration meter
Sine multiple signal generating group output 1 (15 stop signal, adjust the output amplitude, make the public noise vibration meter indicate 14B.
Public noise vibration meter is set to sample N,=60 times, sampling time interval is t=15% instrument sampling 1-- [Time, almost 190 seconds, the output of the generator is attenuated, the sample is -200, so according to the chemical 7 continuous results should meet the requirements of this regulation 1.1.1.1, 14 sound level stability verification
Verification method diagram see Tao:
Positive power generator
Diagram center by the handover run set method diagram
Public noise throat production vibration meter
After the public noise Lu vibration meter is turned on and preheated for 15 minutes, the low-noise generator inputs 20 (for vibration level) or 1 cent [H56 (peak value 3) 11 time 1 weighted material verification
Verification point diagram see Figure 4.
Zhengfa Zhongfa three parts
multi-4 fashion meter weighted special grab block diagram
public: must
11.1 vibration level time characteristic verification
JJG9211996
The generator outputs 2012 continuous stop string borrowing signal, the public noise Lu vibration meter is placed in the "acceleration" block, the input signal is adjusted, the public noise movement meter displays 116c mountain t, the sudden sound generator expands a single receiving sound signal of 0.5= duration, keeps the signal amplitude unchanged, the time characteristic of the public noise alarm meter is set to "fast" block, "L" state, and the change of the verification indication value shall comply with the provisions of Section 1.1.6 of this regulation.
Make the sound generator output a single burst sound signal of 4 duration, keep the signal value unchanged, and set the time characteristic of the noise vibration meter to "slow". The change of the indication value during the verification shall comply with the provisions of Item 1.1.6 of this Regulation. 11.2 Verification of sound time characteristic
The burst generator outputs a sinusoidal signal with a frequency of 2000H, and the duration of a single burst is U.2s and U.5s respectively. The noise vibration meter is set to "A" level, and the time characteristic is in the "fast" and "slow" positions. Repeat the above steps. The result shall comply with the provisions of Item 1.1.6 of this Regulation. 12 Verification of wind measurement range lower limit
The equivalent impedance replaces the sensor of the noise vibration meter, and the equivalent noise level at each frequency weight of the noise vibration meter is measured. The value of the equivalent noise level plus 5 is the measurement range lower limit of the noise vibration meter. 13 Statistical calculation function verification
Verification block diagram is shown in Figure 5,
Upstream signal generating part
Precision subtractor
Figure 5 Statistical calculation function diagram
Public noise vibration meter
Sine multiple signal generating group output 1 (15 stop signal, adjust the output amplitude, make the public noise vibration meter indicate 14B.
Public noise vibration meter is set to sample N,=60 times, sampling time interval is t=15% instrument sampling 1-- [Time, almost 190 seconds, the output of the generator is attenuated, the sample is -200, so according to the chemical 7 continuous results should meet the requirements of this regulation 1.1.1.1, 14 sound level stability verification
Verification method diagram see Tao:
Positive power generator
Diagram center by the handover run set method diagram
Public noise throat production vibration meter
After the public noise Lu vibration meter is turned on and preheated for 15 minutes, the low-noise generator inputs 20 (for vibration level) or 1 cent [H
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