第1页 / 共203页
第2页 / 共203页
第3页 / 共203页
第4页 / 共203页
第5页 / 共203页
第6页 / 共203页
第7页 / 共203页
第8页 / 共203页
LabVIEW声音和振动工具包用户手册.pdf
LabVIEW Sound and Vibration Toolkit User Manual
Support
Worldwide Technical Support and Product Information
National Instruments Corporate Headquarters
Worldwide Offices
Important Information
Warranty
Copyright
Trademarks
Patents
WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS
Contents
About This Manual
Conventions
Related Documentation
Chapter 1 Introduction
Sound and Vibration Toolkit
Figure 1-1. Sound and Vibration Toolkit Overview
Toolkit Palettes
Scaling
Calibration
Limit Testing
Weighting
Integration
Generation
Vibration Level
Sound Level
Octave Analysis
Frequency Analysis
Transient Analysis
Waterfall Display
Swept Sine
Distortion
Single-Tone
Front Panel Displays
Examples
Chapter 2 Dynamic Signals
Acquiring and Simulating Dynamic Signals
Figure 2-1. Relationship of the Data Source to the Sound and Vibration Measurement Process
Aliasing
Figure 2-2. Simulated Data Aliasing
Time Continuity
Chapter 3 Scaling and Calibration
Scaling to EU
Figure 3-1. Relationship of Scaling to the Sound and Vibration Measurement Process
Performing System Calibration
Propagation Delay Calibration
Figure 3-2. Measuring the Device Propagation Delay
Figure 3-3. Propagation Delay Measurement of an NI PCI-6052E
Figure 3-4. NI PXI-4461 Propagation Delay with a 204.8 kHz Sample Rate
Figure 3-5. NI PXI-4461 Propagation Delay versus Sample Rate
Figure 3-6. Measuring the DUT Propagation Delay
Chapter 4 Limit Testing Analysis
Limit Testing Overview
Figure 4-1. Relationship of Limit Testing to the Sound and Vibration Measurement Process
Table 4-1. Compatible Data Types for SVT Limit Testing VI
Using the SVT Limit Testing VI
Table 4-2. Criteria for Upper and Lower Limits
Figure 4-2. Range Detection Performed in Engineering Units
Figure 4-3. Range Detection Test on a Time-Domain Signal
Figure 4-4. Test Scalar Measurement
Figure 4-5. Limit Testing on THD Measurements
Figure 4-6. Perform Continuous Mask Test on Power Spectrum
Figure 4-7. Continuous Mask Test on a Power Spectrum
Figure 4-8. Discontinuous Mask Test on Swept-Sine Frequency Response
Figure 4-9. Discontinuous Mask Test on a Swept-Sine Frequency Response
Chapter 5 Weighting Filters
Purpose of Weighting Filters
Figure 5-1. Frequency Response of a Typical Instrumentation-Grade Microphone
Figure 5-2. Equal Loudness Curves
Psophometric Weighting Filters
A-, B-, and C-Weighting Filters
Figure 5-3. Relative Attenuation of A-, B-, and C-Weighting Filters
Radiocommunications Weighting Filters
Figure 5-4. Relative Attenuation of Radiocommunications Weighting Filters
Telecommunications Weighting Filters
Figure 5-5. Relative Attenuation of Telecommunications Weighting Filters
Applying Weighting Filters
Figure 5-6. Relationship of Weighting to the Sound and Vibration Measurement Process
Applying Weighting to Time-Domain Data
Table 5-1. Supported Psophometric Filter Rates
Standards Compliance
A-, B-, and C-Weighting Filters
ANSI Standards
ISO/IEC Standard
Radiocommunications Weighting Filters
Telecommunications Weighting Filters
Performing A-Weighted Sound Level Measurements
Figure 5-7. A-Weighting of a Simulated Time-Domain Signal Block Diagram
Figure 5-8. A-Weighting Response in the Time Domain
Applying Weighting to an Octave Spectrum
Figure 5-9. Applying Weighting to a Third-Octave Spectrum
Errors Due to Uniform Corrections
Figure 5-10. Potential Measurement Error for A-Weighting at Low Frequency
Applying Weighting to an FFT-Based Spectrum
Figure 5-11. Applying Frequency Weighting to a Power Spectrum
Figure 5-12. Applying Weighting before Computing the Power Spectrum
Chapter 6 Integration
Introduction to Integration
Figure 6-1. Integration of a 0.5 Hz Sine Wave
Implementing Integration
Figure 6-2. Relationship of Integration to the Sound and Vibration Measurement Process
Challenges When Integrating Vibration Data
DC Component
Transducers
Implementing Integration using the Sound and Vibration Toolkit
Time-Domain Integration
Single-Shot Acquisition and Integration
Figure 6-3. Block Diagram for Single-Shot Acquisition and Integration
Figure 6-4. Transient Response in Single-Shot Acquisition and Integration
Continuous Acquisition and Integration
Figure 6-5. Continuous Acquisition and Integration
Figure 6-6. Settled Response of Continuous Acquisition and Integration
Figure 6-7. Frequency Response for Single Integration
Figure 6-8. Frequency Response for Double Integration
Frequency-Domain Integration
Figure 6-9. Integration in the Time Domain and in the Frequency Domain
Figure 6-10. Power Spectra of the Integrated Signal
Chapter 7 Vibration-Level Measurements
Figure 7-1. Relationship of Vibration-Level Measurements to the Sound and Vibration Measurement Process
Measuring the Root Mean Square (RMS) Level
Single-Shot Buffered Acquisition
Figure 7-2. Single-Shot Buffered Acquisition and RMS Level VI
Continuous Signal Acquisition
Figure 7-3. Continuous Data Acquisition and RMS Level VI
Performing a Running RMS Level Measurement
Figure 7-4. Running RMS VI
Computing the Peak Level
Computing the Crest Factor
Figure 7-5. Crest Factor VI
Chapter 8 Sound-Level Measurements
Figure 8-1. Relationship of Sound-level Measurements to the Sound and Vibration Measurement Process
Time Averaging Modes
Linear Averaging
Single-Shot Linear Averaging
Figure 8-2. Single-Shot Leq VI
Figure 8-3. Leq and Instantaneous Sound Pressure Level versus Time
Measuring Leq Over a Longer Time Period
Figure 8-4. One Hour Leq VI
Restart Averaging and Advanced Concepts
Figure 8-5. Block Diagram for Reverberation VI
Figure 8-6. 10-Second Reverberation Time Measurement
Performing a Running Leq
Exponential Averaging
Figure 8-7. Exponential Averaging with Slow Time Constant VI
Peak Hold
Considerations for Making Sound-Level Measurements
Chapter 9 Fractional-Octave Analysis
Figure 9-1. Relationship of Fractional-Octave Analysis to the Sound and Vibration Process
Fractional-Octave Analysis Overview
Full-Octave Analysis in the 31.5 Hz-16 kHz Band
Figure 9-2. Full-Octave Center Frequencies
Figure 9-3. Full-Octave Spectrum
Bandwidth and Filter Banks
The Octave Filter
Figure 9-4. Octave Filter
Bandedge Frequencies
Fractional-Octave Filters
Figure 9-5. Response of 1/3 Octave Filters
Filter Settling Time
Averaging
Linear Averaging
Exponential Averaging
Figure 9-6. 1/3 Octave Analysis with Fast Exponential Averaging VI
Equal Confidence Averaging
Peak-Hold Averaging
Resetting the Filter and Restarting the Averaging Process
Performing Third-Octave Analysis Outside the Audio Range
Figure 9-7. Performing 1/3 Octave Analysis Outside Standard Bands
ANSI and IEC Standards
ANSI Standard
IEC Standard
Nominal Frequencies
Compliance with ANSI and IEC Standards
Displaying Results
Weighting Filters
Chapter 10 Frequency Analysis
Figure 10-1. Relationship of Frequency Analysis to the Sound and Vibration Measurement Process
FFT Fundamentals
Number of Samples
Frequency Resolution
Maximum Resolvable Frequency
Minimum Resolvable Frequency
Number of Spectral Lines
Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
Table 10-1. Time-Domain Specifications to Frequency-Domain Parameters
Table 10-2. Frequency-Domain Specifications to Time-Domain Parameters
Increasing Frequency Resolution
Figure 10-2. Power Spectrum Obtained with an Acquisition Time of 10 ms
Figure 10-3. Power Spectrum Obtained with an Acquisition Time of 1 s
Zoom FFT Analysis
Frequency Resolution of the Zoom FFT VIs
Zoom Measurement
Figure 10-4. Performing a Zoom Power Spectrum Measurement
Figure 10-5. Zoom Power Spectrum Measurement Results
Zoom Settings
Figure 10-6. Zoom Settings Control
Subset Analysis
Using the Frequency Analysis VIs
Available Measurements
Single-Channel Measurements
Power Spectrum Measurement
Figure 10-7. Single-Shot Acquisition
Figure 10-8. Continuous Acquisition
Dual-Channel Measurements
Frequency Response Function Measurement
Figure 10-9. Connection Scheme for FRF Measurement with an NI 4461 Device
Figure 10-10. FRF Block Diagram
Figure 10-11. Time-Domain Stimulus and Response Signals
Figure 10-12. Frequency Response without Averaging
Figure 10-13. Frequency Response with Averaging
Figure 10-14. Frequency Response with 4,096 Samples
Windowing
Figure 10-15. Effect of Windowing on Periodicity
Table 10-3. Supported Time-Domain Windows
Averaging Parameters
Figure 10-16. Averaging Parameters Control
Special Considerations for Averaged Measurements
Averaging Mode
No Averaging
RMS Averaging
Vector Averaging
RMS versus Vector Averaging
Figure 10-17. Effect of Averaging Mode on Averaged Spectrum
Peak Hold
Weighting Mode
Coherence and Coherent Output Power
Extended Measurements
Power in Band
Table 10-4. Power in Band Equations Based on Input Type
Spectrum Peak Search
Unit Conversion
Table 10-5. Desired Scaling Parameters
Chapter 11 Transient Analysis
Figure 11-1. Relationship of Transient Analysis to the Sound and Vibration Measurement Process
Transient Analysis with the Sound and Vibration Toolkit
Performing an STFT versus Time
Figure 11-2. Chirp Signal
Figure 11-3. Baseband FFT on a Chirp Signal
Figure 11-4. Time Segment Control
Selecting the FFT Block Size
Figure 11-5. STFT Using a 1,024 Sample Block Size
Figure 11-6. STFT Using a 4,096 Sample Block Size
Overlapping
Figure 11-7. 50% Overlap
Figure 11-8. Subdivisions of the Time-Domain Waveform
Using the SVT STFT versus Time VI
Figure 11-9. Use of the SVT STFT versus Time VI
Figure 11-10. STFT versus Time Graph
Performing an STFT versus Rotational Speed
Converting the Pulse Train to Rotational Speed
Figure 11-11. Tach Info Control
Figure 11-12. Tachometer Signal
Figure 11-13. Result from SVT Convert to RPM (analog) VI
STFT versus RPM
Figure 11-14. Microphone Signal Obtained during Engine Run-Up
Figure 11-15. Rotational Speed as a Function of Time during Engine Run-Up
Figure 11-16. Intensity Graph of Sound Pressure Level for an Engine Run-Up
Measuring a Shock Response Spectrum
Figure 11-17. SDOF System Response to a Half-Sine Shock
Figure 11-18. Half-Sine Pulse SRS (Maximax)
Figure 11-19. Using the SVT Shock Response Spectrum VI
Figure 11-20. Acquired SRS (Maximax)
Chapter 12 Waterfall Display
Using the Display VIs
Figure 12-1. Waterfall Display for Frequency Analysis
Initializing the Display
Sending Data to the Display
Waterfall Display for Frequency Analysis
Figure 12-2. Waterfall Display for Frequency Analysis VI Block Diagram
Waterfall Display for Transient Analysis
Figure 12-3. STFT VI Block Diagram
Figure 12-4. STFT Waterfall Display
Waterfall Display for Octave Spectra
Figure 12-5. Block Diagram for VI Displaying Octave Spectra
Figure 12-6. Waterfall Display for Octave Spectra Analysis
Customizing the Waterfall Display View
Figure 12-7. Waterfall Graph Controls
Closing the Waterfall Display
Chapter 13 Swept-Sine Measurements
Figure 13-1. Swept-Sine Measurement Flowchart
Swept Sine Overview
Figure 13-2. Sweeping Swept Sine Example
Figure 13-3. Stepping Swept Sine Example
Choosing Swept-Sine versus FFT Measurements
Table 13-1. Swept Sine and FFT Differences
Figure 13-4. Swept-Sine and FFT Measurements
Taking a Swept Sine Measurement
Figure 13-5. Customizing a Swept Sine Measurement
Swept Sine Measurement Example
Figure 13-6. Swept-Sine Measurement Connection Diagram
Figure 13-7. Block Diagram of SVXMPL_Swept Sine FRF DAQmx VI
Table 13-2. Swept Sine Measurement Steps
Figure 13-8. Time Domain Results
Figure 13-9. Magnitude and Phase Response of a 1 kHz Notch Filter
Figure 13-10. THD versus Frequency
Figure 13-11. THD versus Frequency Results
Chapter 14 Distortion Measurements
Variable Definitions
Figure 14-1. Relationship of Distortion Analysis to the Sound and Vibration Measurement Process
Signal in Noise and Distortion (SINAD)
Figure 14-2. Removing DC Voltage from Low-Frequency SINAD Measurement
Figure 14-3. Front Panel of SINAD Measurement VI
Total Harmonic Distortion Plus Noise (THD+N)
Total Harmonic Distortion (THD)
Figure 14-4. Distortion Test VI
Figure 14-5. Distortion Test Measured Magnitude Spectrum
Table 14-1. Distortion Test Measurement Results
Intermodulation Distortion (IMD)
Figure 14-6. IMD Test Signal with High-Frequency Carrier Tone Sidebands
Figure 14-7. IMD Components as Multiples of the Difference Frequency
Table 14-2. IMD Standards and Typical Applications
Phase Linearity
Figure 14-8. Phase Linearity Graph
Figure 14-9. Deviation of the Measured Phase
Chapter 15 Single-Tone Measurements
Single-Tone Measurement Overview
Figure 15-1. Dual-Channel Measurement
Figure 15-2. Single-Channel Measurement
Figure 15-3. Relationship of Single-Tone Measurements to the Sound and Vibration Measurement Process
Gain and Phase
Crosstalk
Figure 15-4. Difference between Gain and Phase Measurement and Crosstalk Measurement
Gain
Figure 15-5. Connecting the Amplitude of the Excitation Tone to the Amplitude Input
Idle-Channel Noise
Dynamic Range
Figure 15-6. Measured Spectrum from Dynamic Range Test
Spurious Free Dynamic Range (SFDR)
Figure 15-7. SFDR Test Spectrum
Appendix A References
Appendix B Technical Support and Professional Services
Glossary
Numbers/Symbols
A-B
C-D
E-F
G-H
I-L
M-N
O-P
R-S
T
V-W
Index
A-C
D-E
F
G-I
K-N
O-S
T
V
W-Z
LabVIEW TM
Sound and Vibration Toolkit
User Manual
LabVIEW Sound and Vibration Toolkit User Manual
April 2004 Edition
Part Number 322194C-01
Support
Worldwide Technical Support and Product Information
ni.com
National Instruments Corporate Headquarters
11500 North Mopac Expressway Austin, Texas 78759-3504 USA Tel: 512 683 0100
Worldwide Offices
Australia 1800 300 800, Austria 43 0 662 45 79 90 0, Belgium 32 0 2 757 00 20, Brazil 55 11 3262 3599,
Canada (Calgary) 403 274 9391, Canada (Ottawa) 613 233 5949, Canada (Québec) 450 510 3055,
Canada (Toronto) 905 785 0085, Canada (Vancouver) 514 685 7530, China 86 21 6555 7838,
Czech Republic 420 224 235 774, Denmark 45 45 76 26 00, Finland 385 0 9 725 725 11,
France 33 0 1 48 14 24 24, Germany 49 0 89 741 31 30, Greece 30 2 10 42 96 427, India 91 80 51190000,
Israel 972 0 3 6393737, Italy 39 02 413091, Japan 81 3 5472 2970, Korea 82 02 3451 3400,
Malaysia 603 9131 0918, Mexico 001 800 010 0793, Netherlands 31 0 348 433 466,
New Zealand 0800 553 322, Norway 47 0 66 90 76 60, Poland 48 22 3390150, Portugal 351 210 311 210,
Russia 7 095 783 68 51, Singapore 65 6226 5886, Slovenia 386 3 425 4200, South Africa 27 0 11 805 8197,
Spain 34 91 640 0085, Sweden 46 0 8 587 895 00, Switzerland 41 56 200 51 51, Taiwan 886 2 2528 7227,
Thailand 662 992 7519, United Kingdom 44 0 1635 523545
For further support information, refer to the Technical Support and Professional Services appendix. To comment
on the documentation, send email to techpubs@ni.com.
© 1999–2004 National Instruments Corporation. All rights reserved.
Important Information
Warranty
The media on which you receive National Instruments software are warranted not to fail to execute programming instructions, due to defects
in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. National
Instruments will, at its option, repair or replace software media that do not execute programming instructions if National Instruments receives
notice of such defects during the warranty period. National Instruments does not warrant that the operation of the software shall be
uninterrupted or error free.
A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside of the package before
any equipment will be accepted for warranty work. National Instruments will pay the shipping costs of returning to the owner parts which are
covered by warranty.
National Instruments believes that the information in this document is accurate. The document has been carefully reviewed for technical
accuracy. In the event that technical or typographical errors exist, National Instruments reserves the right to make changes to subsequent
editions of this document without prior notice to holders of this edition. The reader should consult National Instruments if errors are suspected.
In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it.
EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CUSTOMER’S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF
NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER. NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR
DAMAGES RESULTING FROM LOSS OF DATA, PROFITS, USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY
THEREOF. This limitation of the liability of National Instruments will apply regardless of the form of action, whether in contract or tort, including
negligence. Any action against National Instruments must be brought within one year after the cause of action accrues. National Instruments
shall not be liable for any delay in performance due to causes beyond its reasonable control. The warranty provided herein does not cover
damages, defects, malfunctions, or service failures caused by owner’s failure to follow the National Instruments installation, operation, or
maintenance instructions; owner’s modification of the product; owner’s abuse, misuse, or negligent acts; and power failure or surges, fire,
flood, accident, actions of third parties, or other events outside reasonable control.
Copyright
Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying,
recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National
Instruments Corporation.
Trademarks
LabVIEW™, National Instruments™, NI™, ni.com™, and NI-DAQ™ are trademarks of National Instruments Corporation.
Product and company names mentioned herein are trademarks or trade names of their respective companies.
Patents
For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file
on your CD, or ni.com/patents.
WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS
(1) NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF
RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN
ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT
INJURY TO A HUMAN.
(2) IN ANY APPLICATION, INCLUDING THE ABOVE, RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE
IMPAIRED BY ADVERSE FACTORS, INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY,
COMPUTER HARDWARE MALFUNCTIONS, COMPUTER OPERATING SYSTEM SOFTWARE FITNESS, FITNESS OF COMPILERS
AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION, INSTALLATION ERRORS, SOFTWARE AND
HARDWARE COMPATIBILITY PROBLEMS, MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL
DEVICES, TRANSIENT FAILURES OF ELECTRONIC SYSTEMS (HARDWARE AND/OR SOFTWARE), UNANTICIPATED USES OR
MISUSES, OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER (ADVERSE FACTORS SUCH AS THESE ARE
HEREAFTER COLLECTIVELY TERMED “SYSTEM FAILURES”). ANY APPLICATION WHERE A SYSTEM FAILURE WOULD
CREATE A RISK OF HARM TO PROPERTY OR PERSONS (INCLUDING THE RISK OF BODILY INJURY AND DEATH) SHOULD
NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE. TO AVOID
DAMAGE, INJURY, OR DEATH, THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO
PROTECT AGAINST SYSTEM FAILURES, INCLUDING BUT NOT LIMITED TO BACK-UP OR SHUT DOWN MECHANISMS.
BECAUSE EACH END-USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS' TESTING
PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN
COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL
INSTRUMENTS, THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING
THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE
INCORPORATED IN A SYSTEM OR APPLICATION, INCLUDING, WITHOUT LIMITATION, THE APPROPRIATE DESIGN,
PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION.
Contents
About This Manual
Conventions ...................................................................................................................xi
Related Documentation..................................................................................................xii
Chapter 1
Introduction
Sound and Vibration Toolkit .........................................................................................1-1
Toolkit Palettes ..............................................................................................................1-2
Scaling .............................................................................................................1-3
Calibration .......................................................................................................1-3
Limit Testing ...................................................................................................1-3
Weighting ........................................................................................................1-3
Integration........................................................................................................1-4
Generation .......................................................................................................1-4
Vibration Level................................................................................................1-4
Sound Level.....................................................................................................1-4
Octave Analysis...............................................................................................1-4
Frequency Analysis .........................................................................................1-4
Transient Analysis ...........................................................................................1-5
Waterfall Display.............................................................................................1-5
Swept Sine .......................................................................................................1-5
Distortion.........................................................................................................1-5
Single-Tone .....................................................................................................1-6
Front Panel Displays......................................................................................................1-6
Examples........................................................................................................................1-6
Chapter 2
Dynamic Signals
Acquiring and Simulating Dynamic Signals .................................................................2-1
Aliasing............................................................................................................2-3
Time Continuity...............................................................................................2-4
Chapter 3
Scaling and Calibration
Scaling to EU .................................................................................................................3-1
Performing System Calibration .....................................................................................3-3
Propagation Delay Calibration ........................................................................3-3
© National Instruments Corporation
v
LabVIEW Sound and Vibration Toolkit User Manual
Contents
Chapter 4
Limit Testing Analysis
Limit Testing Overview ................................................................................................ 4-1
Using the SVT Limit Testing VI ................................................................................... 4-3
Chapter 5
Weighting Filters
Purpose of Weighting Filters......................................................................................... 5-1
Psophometric Weighting Filters...................................................................... 5-3
A-, B-, and C-Weighting Filters ....................................................... 5-3
Radiocommunications Weighting Filters ......................................... 5-5
Telecommunications Weighting Filters............................................ 5-6
Applying Weighting Filters........................................................................................... 5-6
Applying Weighting to Time-Domain Data ................................................... 5-8
Standards Compliance ................................................................................................... 5-9
A-, B-, and C-Weighting Filters...................................................................... 5-9
ANSI Standards ................................................................................ 5-9
ISO/IEC Standard ............................................................................. 5-10
Radiocommunications Weighting Filters........................................................ 5-10
Telecommunications Weighting Filters .......................................................... 5-10
Performing A-Weighted Sound Level Measurements...................... 5-11
Applying Weighting to an Octave Spectrum .................................................. 5-12
Errors Due to Uniform Corrections .................................................. 5-12
Applying Weighting to an FFT-Based Spectrum ........................................... 5-13
Chapter 6
Integration
Introduction to Integration............................................................................................. 6-1
Implementing Integration .............................................................................................. 6-3
Challenges When Integrating Vibration Data................................................. 6-5
DC Component ................................................................................. 6-5
Transducers....................................................................................... 6-5
Implementing Integration using the Sound and Vibration Toolkit ................. 6-5
Time-Domain Integration.............................................................................................. 6-6
Single-Shot Acquisition and Integration......................................................... 6-6
Continuous Acquisition and Integration ......................................................... 6-7
Frequency-Domain Integration ..................................................................................... 6-11
LabVIEW Sound and Vibration Toolkit User Manual
vi
ni.com
Contents
Chapter 7
Vibration-Level Measurements
Measuring the Root Mean Square (RMS) Level ...........................................................7-2
Single-Shot Buffered Acquisition ...................................................................7-3
Continuous Signal Acquisition........................................................................7-3
Performing a Running RMS Level Measurement .........................................................7-4
Computing the Peak Level.............................................................................................7-4
Computing the Crest Factor...........................................................................................7-5
Chapter 8
Sound-Level Measurements
Time Averaging Modes .................................................................................................8-2
Linear Averaging.............................................................................................8-3
Single-Shot Linear Averaging ..........................................................8-3
Measuring Leq Over a Longer Time Period ......................................8-4
Restart Averaging and Advanced Concepts......................................8-5
Performing a Running Leq.................................................................8-6
Exponential Averaging....................................................................................8-7
Peak Hold ........................................................................................................8-8
Considerations for Making Sound-Level Measurements ..............................................8-8
Chapter 9
Fractional-Octave Analysis
Fractional-Octave Analysis Overview...........................................................................9-2
Full-Octave Analysis in the 31.5 Hz–16 kHz Band ........................................9-3
Bandwidth and Filter Banks ..........................................................................................9-4
The Octave Filter.............................................................................................9-4
Bandedge Frequencies.....................................................................................9-5
Fractional-Octave Filters .................................................................................9-6
Filter Settling Time..........................................................................................9-7
Averaging.......................................................................................................................9-8
Linear Averaging.............................................................................................9-8
Exponential Averaging....................................................................................9-8
Equal Confidence Averaging ..........................................................................9-9
Peak-Hold Averaging ......................................................................................9-9
Resetting the Filter and Restarting the Averaging Process .............................9-9
Performing Third-Octave Analysis Outside the Audio Range ......................................9-9
ANSI and IEC Standards ...............................................................................................9-10
ANSI Standard.................................................................................................9-10
IEC Standard ...................................................................................................9-11
© National Instruments Corporation
vii
LabVIEW Sound and Vibration Toolkit User Manual
Contents
Nominal Frequencies ...................................................................................... 9-11
Compliance with ANSI and IEC Standards.................................................... 9-11
Displaying Results......................................................................................................... 9-12
Weighting Filters ........................................................................................................... 9-12
Chapter 10
Frequency Analysis
FFT Fundamentals......................................................................................................... 10-2
Number of Samples......................................................................................... 10-3
Frequency Resolution ..................................................................................... 10-3
Maximum Resolvable Frequency ..................................................... 10-4
Minimum Resolvable Frequency...................................................... 10-4
Number of Spectral Lines................................................................. 10-4
Relationship between Time-Domain and Frequency-Domain
Specifications and Parameters...................................................................... 10-4
Increasing Frequency Resolution .................................................................................. 10-6
Zoom FFT Analysis ........................................................................................ 10-8
Frequency Resolution of the Zoom FFT VIs.................................... 10-9
Zoom Measurement .......................................................................... 10-10
Zoom Settings................................................................................... 10-11
Subset Analysis ............................................................................................... 10-11
Using the Frequency Analysis VIs ................................................................................ 10-12
Available Measurements................................................................................. 10-12
Single-Channel Measurements ....................................................................... 10-13
Power Spectrum Measurement......................................................... 10-14
Dual-Channel Measurements.......................................................................... 10-15
Frequency Response Function Measurement ................................... 10-15
Windowing .................................................................................................................... 10-21
Averaging Parameters ................................................................................................... 10-22
Special Considerations for Averaged Measurements ..................................... 10-23
Averaging Mode ............................................................................................. 10-23
No Averaging ................................................................................... 10-24
RMS Averaging ................................................................................ 10-24
Vector Averaging ............................................................................. 10-25
RMS versus Vector Averaging......................................................... 10-25
Peak Hold ......................................................................................... 10-27
Weighting Mode ............................................................................................. 10-27
Coherence and Coherent Output Power ........................................................................ 10-28
Extended Measurements................................................................................................ 10-28
Power in Band................................................................................................. 10-29
Spectrum Peak Search..................................................................................... 10-29
Unit Conversion .............................................................................................. 10-30
LabVIEW Sound and Vibration Toolkit User Manual
viii
ni.com
Contents
Chapter 11
Transient Analysis
Transient Analysis with the Sound and Vibration Toolkit ............................................11-2
Performing an STFT versus Time .................................................................................11-2
Selecting the FFT Block Size ..........................................................................11-5
Overlapping .....................................................................................................11-6
Using the SVT STFT versus Time VI.............................................................11-8
Performing an STFT versus Rotational Speed ..............................................................11-9
Converting the Pulse Train to Rotational Speed .............................................11-9
STFT versus RPM ...........................................................................................11-10
Measuring a Shock Response Spectrum........................................................................11-12
Chapter 12
Waterfall Display
Using the Display VIs....................................................................................................12-1
Initializing the Display ....................................................................................12-2
Sending Data to the Display ............................................................................12-2
Waterfall Display for Frequency Analysis........................................12-3
Waterfall Display for Transient Analysis .........................................12-3
Waterfall Display for Octave Spectra ...............................................12-5
Customizing the Waterfall Display View........................................................12-6
Closing the Waterfall Display .........................................................................12-6
Chapter 13
Swept-Sine Measurements
Swept Sine Overview.....................................................................................................13-3
Choosing Swept-Sine versus FFT Measurements .........................................................13-4
Taking a Swept Sine Measurement ...............................................................................13-6
Swept Sine Measurement Example ...............................................................................13-7
Chapter 14
Distortion Measurements
Variable Definitions.......................................................................................................14-1
Signal in Noise and Distortion (SINAD).......................................................................14-3
Total Harmonic Distortion Plus Noise (THD+N)..........................................................14-5
Total Harmonic Distortion (THD) .................................................................................14-6
Intermodulation Distortion (IMD) .................................................................................14-9
Phase Linearity ..............................................................................................................14-12
© National Instruments Corporation
ix
LabVIEW Sound and Vibration Toolkit User Manual
相关推荐
2023年江西萍乡中考道德与法治真题及答案.doc
2012年重庆南川中考生物真题及答案.doc
2013年江西师范大学地理学综合及文艺理论基础考研真题.doc
2020年四川甘孜小升初语文真题及答案I卷.doc
2020年注册岩土工程师专业基础考试真题及答案.doc
2023-2024学年福建省厦门市九年级上学期数学月考试题及答案.doc
2021-2022学年辽宁省沈阳市大东区九年级上学期语文期末试题及答案.doc
2022-2023学年北京东城区初三第一学期物理期末试卷及答案.doc
2018上半年江西教师资格初中地理学科知识与教学能力真题及答案.doc
2012年河北国家公务员申论考试真题及答案-省级.doc
2020-2021学年江苏省扬州市江都区邵樊片九年级上学期数学第一次质量检测试题及答案.doc
2022下半年黑龙江教师资格证中学综合素质真题及答案.doc
