1. Introduction to Peakvue

2. Objectives To Understand: 1. What Peakvue Is! 2. How it Works!
3. Filter Options
Types of filters available
Calculating the correct filter setting
Filter Guidelines
4. Peakvue Data
Spectrums and Waveforms
Diagnosing Faults
5. Peakvue Versus Demodulation Techniques
6. Acquiring Peakvue Data using the 2120A

3. What is Peakvue™ What is Peakvue?
Peakvue is a technology unique to CSI and means ‘Peak Value’
Such as the Peak Value of an impact generated by a bearing defect in a time waveform - (True Peak Value)
If you have a 21XX analyzer you have the capability to acquire ‘Peakvue Data’
The ‘True Peak Value’ is obtained by concentrating on ‘Stress Wave Analysis’ rather than conventional vibration data.
These stress waves travel further than conventional vibration signals so a truer indication of fault severity is obtained.

4. What is Peakvue™ What is a Stress Wave?
Stress waves accompany metal-metal impacting. These stress waves are short-term (fractional to a few milliseconds) transient events, which introduce a ripple effect on the surface machinery as they propagate away from the initial event.
If you think of a stone being dropped into a pool of water. The stone is the initial impact generated by the fault. The effect of the stone being dropped into the water cause a ripple on the surface of the water which, spreads over a wide area.
Initial Impact

5. What is Peakvue
If a bearing has a sub-surface defect (early bearing wear), when a rolling element passes over the defect it bends the race slightly and then as the rolling element passes it restores back to it’s natural state.
This event causes a high frequency (1-50KHz) short duration stress wave.
This is what Peakvue detects

6. How Does It Work?
Digital
Peak
Impact
Detection
Vibration
Signal
High
Pass
Filter
Full
Wave
Rectify
FFT
A comparison can be made of the sampling to show how data is collected through both methods of data acquisition, normal and Peakvue™.

7. How Does It Work? Instantaneous Samples
The diagram below shows sampling of data using normal data collection.
Stress wave- this is missed under normal conditions
Instantaneous Samples

8. How Does It Work? Peakvue Samples
The diagram below shows sampling of data using Peakvue™ data collection.
Stress wave- this is missed under normal conditions
Peakvue Samples

9. How Does It Work?
Peakvue measures the highest amplitude found in a stress waves (Pk Value) and holds that data
The waveform data is then passed through a high pass filter to remove the unwanted, low frequencies
Imbalance, Misalignment, Looseness, resonance etc.
This just leaves us with the high frequency impacting data (Peak) above the machine noise level
The data is then brought back to fundamental frequency. (this allows analysis of the data to be done quicker and easier)

10. Types of filter available Filter Calculations Filter Guidelines
Filters
Types of filter available
Filter Calculations
Filter Guidelines

11. Filters Options
One of the key elements in acquiring meaningful peakvue data is the selection of ‘filters’
Selecting the wrong type of filter will result in poor quality data
To much noise filtered through (the spectrum becomes very noisy)
To much is filtered out (The stress wave is not allowed to pass through)
There are two types of filter options in Peakvue, these are:
1. Band Pass Filter
2. High Pass Filter
Each of the filters are designed to remove unwanted data out of the signal at the appropriate levels

12. Filter Options - ‘High Pass Filter’
High Pass Filters remove all frequencies from the data below the filter setting but allow the high frequency stress wave to pass through.
All low frequencies are removed from the input signal
Stress Wave data is allowed to pass through the filter
High Pass Filter

13. Filter Options - ‘Band Pass Filters’
Looks for stress waves within a parameter defined by the filter setting. Frequencies above and below this setting are removed from the data
Data is filtered out of the signal
Data passes through filter

14. Filter Selection
To select the correct filter we need to consider the highest operational defect frequency that we want to measure/detect. Then select the next available filter above that frequency
E.g.
Consider a typical motor / pump arrangement. We have:
1 - 4 Pole A.C. Induction Motor
2 - 3 Jaw Coupling
3 - Centrifugal Pump
Typically the highest defect frequency to emit from this machine would be?
1 - BPFI - Bearing Defect

15. Filter Selection
4 Pole Motor A.C Induction fitted with bearings SKF 6313
Defect Frequencies (Orders)
FTF
BSF
BPFO
BPFI
Typically we would want to see the 10th Harmonic of the BPFI
Highest defect frequency:
(BPFI x 10) x Turning Speed (Hz)
(4.929 x 10) x 25 Hz
We would then select the next available filter setting above the frequency

16. Available filters High Pass Filters Band Pass Filters
500hz
1000hz
2000hz
5000hz
10000hz
20000hz
Band Pass Filters
20hz – 150hz
50hz – 300hz
100hz – 600hz
500hz – 1khz
From our previous calculation of 1232Hz, What filter setting would we select?
Note: the meter will only allow you to select the next filter above the specified Fmax.

17. Filter uses (Band Pass) - Guidelines
Band Pass Filters
20hz – 150hz Felt problems on paper machines
50hz – 300hz Certain structural resonance excitation, modulation of gearmesh in low speed machinery
100hz – 600hz Gearmesh modulation in intermediate speed machinery.
500hz – 1khz Gearmesh modulation
Tip: use bandpass filters when the event of interest is the excitation of a structural resonance, or the modulation of known frequencies – such as gearmesh.

18. Filter uses (Highpass) - guidelines
High Pass filters
500hz Low speed machinery having <125hz. Bearing & gearing problems
1000hz Intermediate speed machinery (<2000 rpm) with gear mesh <300hz
2000hz Medium speed machinery (<4000rpm) with gear mesh ,600hz
5000hz Machinery up to 9000rpm and gear mesh to 1500hz, Requires attention be paid to how the sensor is mounted as well as the sensors frequency response.
10000hz High speed machinery with gear mesh up to 3000hz sensor must be permanently mounted with a frequency response of 3db in the 30kHz or higher range.
20000hz High speed machinery with gearmesh up to 6000hz. Sensor must be high frequency and permanently mounted.
Tip: Use highpass filters when the objective is to detect stress waves which are emitted by metal on metal impacting.

19. Filter Selection - Question
Consider:
Motor running at a speed of 1000RPM
Driving a fan unit via pulley belts
Fan Speed is 1350RPM
Motor Bearings = SKF BPFI 4.855
Fan Bearings = SKF BPFI 5.907
Calculate what Filter setting would be required for both the motor and the fan bearings?
Filters Available:
500 Hz, Hz, Hz, Hz, Hz, Hz. (High Pass)
20-150Hz, Hz, Hz, KHz. (Band Pass)

20. Filter Selection - Answers
Motor Speed = 1000CPM / 60 = Hz
Fan Speed = 1350CPM / 60 = 22.5Hz
Motor.
BPFI = 4.855
Defect Frequency = (BPFI x 10) x Turning Speed (Hz)
Defect Frequency = (4.855 x 10) x
Defect Frequency = Hz
Filters Available:
500 Hz, Hz, Hz, Hz, Hz, Hz. (High Pass)
20-150Hz, Hz, Hz, KHz. (Band Pass)
1000Hz

21. Filter Selection - Answers
Motor Speed = 1000CPM / 60 = Hz
Fan Speed = 1350CPM / 60 = 22.5Hz
Fan
BPFI = 5.907
Defect Frequency = (BPFI x 10) x Turning Speed (Hz)
Defect Frequency = (5.907 x 10) x 22.5
Defect Frequency = Hz
Filters Available:
500 Hz, Hz, Hz, Hz, Hz, Hz. (High Pass)
20-150Hz, Hz, Hz, KHz. (Band Pass)
2000Hz

22. Spectrums and Waveforms Diagnostics Techniques
Peakvue Data
Spectrums and Waveforms
Diagnostics Techniques

23. Peakvue - Spectrum Here is a typical Peakvue spectra plot.
2. Units should be ‘acceleration’ (Very high frequency analysis)
1. Broad band energy - Filtered Noise
3. Amplitude values are low. Severity of fault is not determined in the spectra
This is typically a GOOD spectrum

24. Peakvue - Spectrum
This is a Peakvue spectrum where high frequency stress waves are being detected
Notice the Impacts passing through the filtered noise
2. Units still in ‘acceleration’ (Very high frequency analysis)
1. Broad band energy - Filtered Noise
3. Amplitude values are low. Remember severity of fault is not determined in the spectra
This is indication of a fault developing

25. Peakvue - Waveforms
Waveforms can be confused with spectrums, as the waveform is only plotting the peak value and does not show a full wave.
2. Peak Value Impacts
4. Acceleration as default units
1. Filtered Noise Level
3. No Peak Negative Value

26. Peakvue - Diagnostics
Diagnosing a Peakvue spectrum and waveform is not to dissimilar to that of conventional data.
However there are a few differences which can be a bit confusing at first, these are:
1. Do not try to locate 1xTurning Speed, as this is low frequency data and will be filtered out.
Turning speed should be entered using the conventional spectral data.
2. Multiple harmonics are often present within a spectrum due to the way peakvue samples the data.
These do not indicate ‘Looseness’
3. Spectral amplitudes are always low in amplitude but should not be used to judge severity. Use the spectrum to diagnose the fault.
4. Waveforms indicate the severity of the problem.

27. Peakvue - Diagnostics Continued…..
5. Ensure the same filter setting is used in both the spectrum and waveform.
Potential faults can be missed or overlooked if different filters are used.
6. Cage Defects show up well in peakvue data and is normally an indication the bearing is under stress.
7. All low frequency faults are removed from the data and will not be seen in a Peakvue spectrum and waveform
Imbalance, Misalignment, Looseness, Resonance - All Gone.

28. Peakvue - Diagnostics
1.Spectral data indicating a defect at Orders
2. Impacting also being detected at 0.6G-s
3. Very Slow RPM

29. Peakvue - Diagnostics
4.Fault Frequencies Indicate a BPFI Defect

30. Peakvue™ Amplitudes - Rolling Element Bearings
For machines running between speeds of RPM recommended guidelines for setting initial warning levels in the Peakvue™ time - waveform are as follows:

31. Peakvue™ Amplitudes - Rolling Element Bearings
For machines running at speeds <900RPM recommended guidelines for setting initial warning levels in the Peakvue™ time- waveform are as follows:

32. Peakvue Vs Demodulation

33. Peakvue Vs Demodulation
What is Demodulation?
This is a technique which concentrates on stress wave analysis, but is not as effective.
How Does it Work?
Demodulation looks for the ringdown that follows an impact, and tries to measure how quickly it fades. In order to do this the ‘Time Waveform’ has to be manipulated in such away that the waveform data becomes useless
Less than 1ms
Initial Impact
Ringdown

34. Peakvue Vs Demodulation
What are the Differences?
Peakvue samples the data much quicker enabling it to catch the very short duration high frequency stress wave. It then holds that ‘Peak Value’ throughout its parameter.
Due to the Analogue filtering system used by Demodulation, results in a ‘delay in response’ and the stress wave impact is missed
Demodulation registers
Peak Impact Detection registers

35. Peakvue Vs Demodulation
The Process!
High
Pass
Filter
Full
Wave
Rectify
Digital
Peak
Impact
Detection
FFT
Peak Impact Detection
Low
Remove DC
Bias
A/D
Converter
Standard Demodulation
Enveloping Stage

36. Peakvue Vs Demodulation
Case Study.
Equipment
A conveyor system consisting of six rolls is driven by a motor/gearbox unit (GMU).
The motor speed is 1500RPM reduced through the gearbox giving the roller speed to be 98.5RPM

37. Peakvue Vs Demodulation
Data was collected on each bearing of the conveyor system
Due to the slow speeds Peakvue and Demodulation Filters were both set to 500Hz High Pass using 1600 Lines of Resolution
Direct Comparison Between the Two
Peakvue
Demodulation
Demodulation Spectra
Peakvue Spectra

38. Peakvue Vs Demodulation
Peakvue Waveform
Demodulation Waveform

39. Acquiring Peakvue Data
Setting up the 2120A
Creating a Peakvue AP Set

40. Setting up the 2120A
Peakvue can be accessed from the ‘Analysis Expert’ options found among the command keys of the 2120A
There are two ways of acquiring peakvue data within the 2120A
Bearing/Gear Analysis - Peakvue
Preset to acquire Peakvue data based upon the AP set assigned to the machine
User Setup Option
Allows user interface to define their own parameters

41. Setting up the 2120A User Set-up Option Lines of Resolution
Define the Fmax you wish to go to. Remember the Fmax is going to define your filter setting.
KCPM = 500Hz High Pass
KCPM = 1000Hz High Pass
KCPM = 2000Hz High Pass
120v KCPM = 5000Hz High Pass
Lines of Resolution
These have to be good enough to capture the FTF of a bearing, which would equate to around 15 Revolutions of waveform data.
Number of Revs = Number of lines / Fmax(Orders)
E.g. 800 Lines over an Fmax of 60 Orders = 13.3 Revolutions (Inadequate)
1600 Lines over an Fmax of 60 Orders = 26.6 Revolutions (OK)

42. Setting up the 2120A Averages Units
This has to be set to 1 Average to gain the ‘true peak’ value.
If you start averaging the data then a stress wave detected in the first average that is not there in the second will lose it’s true amplitude when averaged together.
Units
The default unit for peakvue is ‘Acceleration’. Remember we are trying to detect very high frequency events, well above conventional vibration data. Acceleration accentuates high frequencies.
Sensor units can be used if using an accelerometer, however CSI recommend a minimum mounting of a ‘Rare Earth Magnet’ for data collection
By using the ‘Page Down’ Button we can toggle through the pages until we find our Peakvue Options (Page 4 of 4)
We turn Peakvue to ‘Yes’
The Pre-filter can now be changed to our required HP Setting

43. Setting up the 2120 Data collection can now commence.
Check the data once collection has finished
Look for:
Impacts in both spectrum and waveform
Amplitude levels of the Waveform
quality of the data
If a problem is detected you may want to acquire more data with a different filter setting.
Remember to store the data once the reading has been taken
At least one Peakvue point should be applied to each critical machine to detect early bearing wear, gearwear or adverse metal to metal contact.
This will need building in the database and adding to the route

44. Analysis Parameter Setup Mastertrend and RBMware
Peakvue™
Analysis Parameter Setup
Mastertrend and RBMware

45. Peakvue™ AP Set up I Open Database Management
Select Analysis Parameter

46. Peakvue™ AP Set up II
Complete the spectrum setup, specifying Fmax, LOR and averages (1).
Specify the number of parameters - 2

47. Peakvue™ AP Set up III Check, ‘Use Analog pre-processor
Select Peakvue, under the ‘Envelope Demodulator’
Select the filter setting.

48. Peakvue™ AP Set up IV
Uncheck, ‘obtain special time waveform?’ - As Default units will be acceleration
Discard all settings when this is unchecked

49. Peakvue™ AP Set up V
Complete Analysis Parameter specifications, the most important parameter is the ‘peak to peak’ waveform parameter.
Ensure ‘unit type’ is acceleration

50. Gearbox case study

51. Diagram G1 G3 G4 G5 G6 G7 G8 G9
G10
G11
G12 M1 M2

52. Introduction
The above gearbox had been overhauled in the workshop and was on its final test run. A vibration signature was taken to confirm a small knock believed to be coming from the coupling, and prove the gearbox was OK.
The readings were taken using Peakvue and standard Vibration Technology on the corresponding points indicated in the diagram above. The following spectrum where obtained.

53. The standard spectrum below was taken from G5. Is there a Problem?
Standard Data
The standard spectrum below was taken from G5. Is there a Problem? G1 G3 G4 G5 G6 G7 G8 G9
G10
G11
G12 M1 M2

54. PeakVue™ Data
The Peakvue reading shows distinct energy at Hz and multiple harmonics of this which is the running speed of the third shaft. The bottom waveform shows clearly a substantial impacting of up to 12 G’s occurring each revolution.

55. The fault
The diagram below indicates the location of the suspected gear fault and was diagnosed as possibly a damaged tooth G1 G3 G4 G5 G6 G7 G8 G9
G10
G11
G12 M1 M2
Faulty Gear
When the gearbox was re-stripped and examined a cracked tooth on the gear identified was found.