The document provides an introduction to vibration analysis, including: 1) An overview of key concepts in vibration measurement such as transducers, sampling, filtering, windows, averaging, and FFT analysis. 2) A discussion of rotating machinery analysis techniques like order tracking and synchronous signal averaging. 3) Details about vibration sources in machines, measurement techniques, and common vibration measures.

1. 1 Caption Data LimitedIntroduction to Vibration Analysis www.captiondata.com

2. 2 Caption Data Limited Introduction to Vibration Analysis Schedule Introduction to Vibration measurements Transducers Acceleration Velocity Displacement Force Sampling Aliasing Leakage Filtering www.captiondata.com

3. 3 Caption Data LimitedIntroduction to Vibration Analysis Windows Averaging FFT Analysis Spectrum Auto Spectrum PSD Cross Spectrum Transfer Function Coherence Real/Imaginary Nyquist www.captiondata.com

4. 4 Caption Data LimitedIntroduction to Vibration Analysis Rotating Machinery Analysis Order tracking Synchronous Signal Averaging Basic Modal Analysis Data Acquisition Windowing Data quality Modeling Resonant Frequency Non Destructive Testing (NDT) Machine Health Monitoring (TOMAS) www.captiondata.com

5. 5 Caption Data Limited Introduction to Vibration Analysis Accelerometers The Model 353B03 is a quartz shear ICP® accelerometer designed for general purpose measurements. It has a sensitivity of 10 mV/g. The quartz shear-mode sensing elements reduce sensitivity to adverse environmental inputs, such as thermal transients, base strain, and transverse motion. The Model 353B03 features a side-exit, 10-32 coaxial connector. Its frequency range of 1 to 7 000 Hz (±5 %) makes this sensor an ideal candidate for general purpose vibration measurements such as vehicle studies, product qualification studies, structural response tests and vibration control www.captiondata.com

6. 6 Caption Data Limited Introduction to Vibration Analysis Accelerometers Miniature accelerometers are designed specifically to meet minimum size and weight requirements. Model 352C22 offers a 1 to 8 000 Hz (±5%) frequency range and a sensitivity of 10 mV/g. With a mass of only 0.017 oz (0,5 gm), this sensor excels in testing of lightweight, flexible structures, such as printed circuit boards, disk drives, and those requiring a low-profile unit. www.captiondata.com

7. 7 Caption Data Limited Introduction to Vibration Analysis Accelerometers The Model 356B11 is a miniature, four-gram, hermetically sealed titanium accelerometer. The hermetic titanium case provides a rugged, reliable sensor for minimal mass loading in triaxial vibration measurements. The 10 mV/g output from ceramic shear mode sensing elements provides a wide measurement range from 2 to 10 000 Hz (±5%) in the "Z" axis and 2 to 7 000 Hz (±5%) in the "X" and "Y" axes. The 5 ft integral shielded cable terminates in a four-pin connector. www.captiondata.com

8. 8 Caption Data Limited Introduction to Vibration Analysis Velocity Transducers www.captiondata.com

9. 9 Caption Data Limited Introduction to Vibration Analysis Displacement Transducers Proximity ProbesThese transducers allow direct observation of shaft or target displacement for a variety of vibration, position, speed, and timing (i.e., phase) measurements. Various tip diameters and thread sizes/configurations are offered to allow measurement ranges as small as 200 micro inches to as large as 1 inch (typically used for differential expansion measurements on large steam turbines), and everything in between, including the popular 80 mil range used for the majority of machinery measurements. www.captiondata.com

10. 10 What are the Componentsof Vibration? Amplitude Maximum value of vibration Frequency Number of events or cycles per unit time Phase Time relationship between vibrations of the same frequency www.captiondata.com

11. 11 Vibration SourcesNatural Frequencies / Resonance Machine Design Induced Machine Structure Mass and Stiffness Damping Resonance When a forcing frequency excites a natural frequency In rotating machinery, “Critical Speed” www.captiondata.com

12. 12 Vibration SourcesForcing Frequencies Machine Design Universal Joints Asymmetrical Shafts, Cams Gear Mesh Couplings Bearings Pumps & Fans Reciprocating Machines Motors / Generators Machine Faults Mass Unbalance Misalignment Bent Shaft Mechanical Looseness Casing / Foundation Distortion Bearing Faults Motor Faults www.captiondata.com

13. 13 How is Vibration Measured? Primitive, Qualitative Methods / Senses Can you actually SEE movement? Can you HEAR something different? What does it FEEL like? Does it SMELL funny? TASTE, not really recommended! www.captiondata.com

14. 14 How is Vibration Measured? Better, Quantifiable Methods / Amplitude Movement / Displacement Speed / Velocity Acceleration www.captiondata.com

15. 15 Sensors Physical Movement / Displacement Proximity Probes Velocity / Speed Velocity Transducers Acceleration Accelerometers www.captiondata.com

16. 16 Vibration Units ‘English’ Units Pounds (lb) / Inch (in.) / Second (sec) Displacement in mils, 1 mil = 1/1000th Inch Peak-to-peak measure Velocity in Inches per second (in/sec or ips) Peak or RMS measure Acceleration in gs, 1 g = 386.1 in/sec 2 Peak or RMS measure www.captiondata.com

17. 17 Frequency / Rotational Units Vibration Frequencies are expressed as: Cycles per Minute (CPM) or Cycles per Second (HZ) Machine or Shaft Speed: Revolutions per Minute (RPM) Phase is expressed as: Degrees, 360 degrees per revolution. May also be expressed as Leading or Lagging www.captiondata.com

18. 18 Relationship of Amplitude, Velocity & Frequency Any Quantity can be Calculated If the remaining two Quantities are Known www.captiondata.com

20. V = (2 π f) D

21. V = Velocity in Inches per second (ips)

22. π (pi) = 3.14159 (or, the button on your calculator)

23. f = Frequency in Hz

24. D = Displacement in mils peakwww.captiondata.com

26. If… V = (2 π f) D

27. Then… D = V / (2 π f)

28. Velocity to Acceleration

29. A = (2 π f) V / 386.1

30. Acceleration to Velocity

31. V = A * 386.1 / (2 π f)www.captiondata.com

33. A = D (2 π f)2 / 386.1

34. D= A * 386.1 / (2 π f)2(we’re done now… you can all relax!) www.captiondata.com

35. 22 Machine Vibration Measures www.captiondata.com

36. 23 Machine Design Vibration Sources Eccentric Shafts / Cams Reciprocating Components Pumps & Fans Gears Bearings Couplings Universal Joints Motors & Generators www.captiondata.com

37. 24 Machine Design Vibration Frequencies Eccentric Shafts / Cams Shaft Speed (1 X) and Multiples (Orders) www.captiondata.com

38. 25 Machine Design Vibration Frequencies Reciprocating Machines ½ and Full Multiples of Shaft Speed www.captiondata.com

39. 26 Machine Design Vibration Frequencies Pumps & Fans Vane Pass & Blade Pass Frequencies Shaft Speed X Number of Vanes Shaft Speed X Number of Blades Flow Noise / Cavitations www.captiondata.com

40. 27 Machine Design Vibration Frequencies Gearboxes Gear Mesh Frequencies Shaft Speed X Number of Teeth www.captiondata.com

41. 28 Machine Design Vibration Sources Bearing Frequencies, Rolling Element Bearings BPFI – Ball Pass Freq. Inner Race BPFO -- Ball Pass Freq. Outer Race BSF – Ball Spin Frequency FTF -- Fundamental Train Frequency Max Range Approximation: Shaft Speed X Number of Elements X 0.6 www.captiondata.com

42. 29 Machine DesignVibration Sources Bearings, Fluid Film / Sleeve Oil Whirl 0.40 – 0.48 X of Shaft Speed Oil Whip Machinery Operating at > 2 X Critical Speed Oil Whirl Locks onto 2 X Critical www.captiondata.com

43. 30 Machine DesignVibration Sources Couplings Shaft Speed X Number of Jaws www.captiondata.com

44. 31 Machine DesignVibration Sources Universal Joints 2 X Shaft Speed www.captiondata.com

45. 32 Machine DesignVibration Sources Motors & Generators Synchronous Motor Speed (SMS) 2 X Line Frequency / Number of Poles Slip Frequency SMS – Actual Speed www.captiondata.com

46. 33 Minimum Acquisition Frequencies www.captiondata.com

47. 34 Applicable Sensors & Limits Credit: John S. Mitchell, machinery Analysis and Monitoring 2nd edition www.captiondata.com

49. Horizontal 90˚ CLOCKWISE from Vertical

50. Direction of Rotation Not Considered

51. Axial Transducers In the Load ZoneCredit: Ronald L. Eshleman, Basic Machinery Vibration www.captiondata.com

52. 36 Useable Frequency Spans ForAccelerometer Mounting Methods www.captiondata.com

53. 37 Caption Data Limited Introduction to Vibration Analysis Digital Sampling Amplitude Resolution Effects of under sampling Aliasing www.captiondata.com

54. 38 Caption Data Limited Introduction to Vibration Analysis Over Sampling www.captiondata.com

55. 39 Caption Data LimitedIntroduction to Vibration Analysis Minimum Sampling www.captiondata.com

56. 40 Caption Data Limited Introduction to Vibration Analysis Leakage www.captiondata.com

57. 41 Caption Data Limited Introduction to Vibration Analysis Weighting Windows No Window Hanning Blackman Harris Flat Top Exponential Decay Box Car/Rectangular www.captiondata.com

58. 42 Caption Data Limited Introduction to Vibration Analysis Weighting Windows No Window Transient events Fixed frequency Cell centered www.captiondata.com

59. 43 Caption Data Limited Introduction to Vibration Analysis Weighting Windows No Window www.captiondata.com

60. 44 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Hanning Continuous data Good frequency accuracy Most common window May not be suitable for transient data Good for separation of closely spaced frequencies www.captiondata.com

61. 45 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Hanning www.captiondata.com

62. 46 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Blackman Harris Similar characteristics to Hanning Continuous data Good frequency accuracy Most common window May not be suitable for transient data Good for separation of closely spaced frequencies www.captiondata.com

63. 47 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Blackman Harris www.captiondata.com

64. 48 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Flat Top Best amplitude Accuracy Frequency accuracy is sacrificed Continuous data Common window for order tracking www.captiondata.com

65. 49 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Flat Top www.captiondata.com

66. 50 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Exponential Decay Used for Bump (impact) testing in Modal Analysis Used for response channels only Decay is adjustable to eliminate leakage Adds artificial damping www.captiondata.com

67. 51 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Exponential Decay www.captiondata.com

68. 52 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Box Car/Rectangular Used in Bump (impact) testing in Modal analysis Used only on the reference channel Adjustable leading and trailing edge Zeros all data outside the window www.captiondata.com

69. 53 Caption Data Limited Introduction to Vibration Analysis Weighting Windows Box Car/Rectangular www.captiondata.com

70. 54 Caption Data Limited Introduction to Vibration Analysis Averaging Linear/Summation Exponential Variable decay Peak Hold Time Synchronous www.captiondata.com

71. 55 Caption Data Limited Introduction to Vibration Analysis Why do we average Improve statistical confidence Extract signals from noise Smooth random vibration www.captiondata.com

72. 56 Caption Data Limited Introduction to Vibration Analysis Linear/Summation Reduces noise Improves statistical accuracy of repetitive or stationary signals. www.captiondata.com

73. 57 Caption Data Limited Introduction to Vibration Analysis Exponential Weights the average count New data carries the most weight Decays the old data Smoothes noise Slows rapidly changing signals www.captiondata.com

74. 58 Caption Data Limited Introduction to Vibration Analysis Peak Hold Updates the spectral line value with a new maximum Holds the maximum until updated www.captiondata.com

75. 59 Caption Data Limited Introduction to Vibration Analysis Time Synchronous Averages in time domain based on a Synchronous event Reduces effects of other operating equipment in close proximity Very good for extracting signals from noise www.captiondata.com

76. 60 Caption Data Limited Introduction to Vibration Analysis www.captiondata.com

77. 61 ZonicBook/618E Hardware Features 8 Vibration Inputs Field expandable to 56 vibration inputs 4 tachometer inputs 8 digital I/O 10/100BaseT Ethernet connection Open ICP and over-range indicators on front panel Signal conditioned output for each input channel www.captiondata.com

78. 62 ZonicBook/618E Hardware Features Software configurable ICP®, DC, or AC coupling 9 input voltage ranges 16 bit, 75 dB dynamic range New rugged package with built-in handle TEDS support www.captiondata.com

79. 63 ZonicBook/618E Hardware Features Expandable up to 56 analog inputs via WBK18 options Other hardware options DBK34A battery/DC UPS www.captiondata.com

80. 64 Caption Data Limited Introduction to Vibration Analysis eZ-Analyst Real Time Vibration Analysis www.captiondata.com

81. 65 eZ-Analyst Real-Time Vibration Measurement and Analysis Two Applications Impact measurement and structure analysis Continuous data recording and transient analysis www.captiondata.com

82. 66 eZ-Analyst – Impact Applications Impact measurements 5 averaging methods Multiple reference channels Interactive displays Cross-channel analysis, FRF, transfer functions Export data to Excel or modal analysis software www.captiondata.com

83. 67 eZ-Analyst – Impact Applications Measurements for Modal Analysis Effect of mass, stiffness, and damping Operating deflection shapes Automatically save after averaging Automatically increase modal locations www.captiondata.com

84. 68 eZ-Analyst– Continuous Data Recording Applications Record “gap-free” data to PC disk Stripchart data analysis and reduction Harmonic, SideBand, and FreeForm Cursors Export data to Excel or eZ-Rotate www.captiondata.com

85. 69 Caption Data Limited Introduction to Vibration Analysis Rotating Machinery Analysis Order Normalization Order tracking www.captiondata.com

86. 70 Caption Data Limited Introduction to Vibration Analysis www.captiondata.com

87. 71 Caption Data Limited Introduction to Vibration Analysis eZ-NDT Non Destructive Testing for Production www.captiondata.com

88. 72 Caption Data Limited Introduction to Vibration Analysis www.captiondata.com

89. 73 Caption Data Limited Introduction to Vibration Analysis Assumptions If test articles are produced in the same manner, and have like properties, then they will have the same natural or resonant frequencies. If the test articles have a change in mass, stiffness or damping, then the resonant or natural frequencies will change. www.captiondata.com

90. 74 Caption Data Limited Introduction to Vibration Analysis What causes the changes? Changes in mass may be caused by void or missing operation in the test article Changes in stiffness may be caused by a material or process variation. Changes in damping can be caused by a material or process variation or a crack in the test article. www.captiondata.com

91. 75 Caption Data Limited Introduction to Vibration Analysis The measurement process The test data is converted into the frequency domain by the analysis software. Key resonant peaks are identified and their frequencies are noted www.captiondata.com

92. 76 Caption Data Limited Introduction to Vibration Analysis The measurement process Known good and defective test articles are tested and compared for shifts in fundamental resonant frequencies. www.captiondata.com

93. 77 Caption Data Limited Introduction to Vibration Analysis The measurement process Each resonant frequency of a known good part is examined and bands are placed around the peak. If the frequency of a tested part is outside of these bands, then the test article fails. www.captiondata.com

94. 78 Caption Data Limited eZ-TOMAS – Applications and Machinery eZ-TOMAS On line condition monitoring and analysis www.captiondata.com

95. 79 Caption Data Limited eZ-TOMAS – Applications and Machinery Petrochemical, Power Utility, Paper and Steel Mill, Pharmaceutical, etc… Turbines, Compressors, Gearboxes, Pumps, Motors, Generators, etc… Typically, 1 to 3 machines per system. 10 to 100,000 RPM range Temporary or Continuous Monitoring www.captiondata.com

96. 80 Vibration Analysis & MonitoringeZ-TOMAS – Gauge Window www.captiondata.com

97. 81 Vibration Analysis & MonitoringeZ-TOMAS – Gauge Window Current Values & Status Vertical Amplitude Circular Phase Limit Checking / Log Events FIFO Storage High Water Marks Relay Outputs www.captiondata.com

98. 82 Vibration Analysis & MonitoringeZ-TOMAS - Configuration Setup Acquisition Fmax: up to 20 KHz Lines: up to 25,600 Hanning / Flat Top FFT Scale Pref: RMS, PK, P-P Input Channels D: DC Cplg, +/- 25V A: ICP, AC Cplg, +/- 5V Gap & Runout Ref. Orbit / Tach Pairs www.captiondata.com

99. 83 Vibration Analysis & MonitoringeZ-TOMAS - Configuration Setup FIFO Storage Up to 200,000 Records/Channel/File RPM Range Change in RPM, Time, Vibration Alarm Condition User Snapshot www.captiondata.com

100. 84 Vibration Analysis & MonitoringeZ-TOMAS - Configuration Setup Spectral Bands OAll, Vdc, 1xA & 1xP 6 User Defined Overall, Peak, Phase Fault Toolkit Spectral Limits 2 High / 2 Low Delay Text Message www.captiondata.com

101. 85 Vibration Analysis & MonitoringRotating Machinery Analysis Orbit, Time Waveform w/ or w/o Filtered N Revolutions Bode w/ or w/o Runout OAll, 1x, nX Waterfall Order Tracks RPM Annotation www.captiondata.com

102. 86 Vibration Analysis & MonitoringRotating Machinery Analysis Polar Runout, Limits Annotation Spectrum Harmonic, Sideband Peak Cursors Shaft Center Line Trend OAll, 1x, nX Cursor to History Location www.captiondata.com

103. 87 Vibration Analysis & MonitoringRotating Machinery Analysis Automatic Tach Analog Inputs Dynamically adjust trigger levels Trigger Direction www.captiondata.com

104. 88 Vibration Analysis & MonitoringLearning Limits Statistical Report Steady State Condition Min, Avg, Max, Dev Calculate Limits based on Normal Operation Before / After Shutdown comparisons www.captiondata.com

105. 89 Vibration Analysis & MonitoringConfiguration Setup – Storage www.captiondata.com

106. 90 Vibration Analysis & MonitoringEdit -Spectral Bands www.captiondata.com

107. 91 Vibration Analysis & MonitoringEdit –Spectral Limits www.captiondata.com

108. 92 Vibration Analysis & MonitoringGauge Window – Monitor Vibration Levels www.captiondata.com

109. 93 Vibration Analysis & MonitoringGauge Window – Monitor Vibration Levels www.captiondata.com

110. 94 Vibration Analysis & MonitoringPlot Windows – Data Source www.captiondata.com

111. 95 Vibration Analysis & MonitoringPlot Windows – Time Waveform www.captiondata.com

112. 96 Vibration Analysis & MonitoringPlot Windows – Spectrum www.captiondata.com

113. 97 Vibration Analysis & MonitoringPlot Windows – Orbit www.captiondata.com

114. 98 Vibration Analysis & MonitoringPlot Windows – Waterfall www.captiondata.com

115. 99 Vibration Analysis & MonitoringPlot Windows – Bode www.captiondata.com

116. 100 Vibration Analysis & MonitoringPlot Windows – Polar www.captiondata.com