Training series

VIBRATION TESTING WEBINAR

Training is a key ingredient to program success

Agenda

• Why vibration testing is important?

• What is the difference between vibration tools?

• Who can best use vibration tools?

•When to use vibration tools?

•How vibration testing is performed?

– Basics of vibration– Simple steps to use vibration tools– Steps for a successful vibration testing program

Why is vibration testing important? Predictability. Studies have shown that vibration testing can provide early warnings of

impending machine failure, giving maintenance staff time to schedule required repairs and acquire needed parts. One customer saved thousands of dollars a year by eliminating unneeded PMs on just 1 machine all with no failures in over 3 years.

Safety. Having information about machine health enables operators to take faulty equipment offline before a hazardous condition occurs.

Revenue. Well-maintained machines have fewer unexpected and serious failures, helping to prevent production stoppages that cut into the bottom line. One customer increased annual production by 4 days adding millions to the company’s bottom line

Increased maintenance intervals. When machine health is being tracked, maintenance can be scheduled by need, not just by accumulated hours of operation. One customer increased intervals by almost 3 years on hundreds of pumps

Reliability. Monitored machinery has fewer unexpected or catastrophic failures. One customer reduced almost daily outages to near zero

Cost savings. Running machinery until failure often results in more expensive repairs, overtime, excessive energy waste, and forced purchases. One customer dropped the annual maintenance budget on a large group of critical pumps in half – hundreds of thousands $

Peace of mind. A better understanding of machine health builds confidence in maintenance schedules, budgeting, and productivity estimates.

What is the difference between vibration tools?

Here’s what happens if we take the machines in a typical plant and put them into a pyramid:Top level - a few complex machines have many variables and require a vibration expert with an analyzer to compare, trend, analyze and diagnose, the machine. See the complex waterfall and analysis on the right. Refer these few machines to a consultant or in-house expert.

Middle level - most of the remaining machines (more than 90 %) are mainstream machines—motors, pumps, fans, compressors and blowers that can effectively be diagnosed using automated diagnostic programs by a technician using the vibration tester.

Bottom level - small and expendable machines that would typically be ignored can now be screened by an operator or entry-level technician using built-in machine health severity scales to indicate when it’s time to call in more advanced tools.

Who can best use vibration tools?• Entry-level technicians use the screening tool to screen for potential problems• Experienced technicians use the tester to diagnose common faults and root cause• Finally, call in a service provider if needed for the few machines at the top of the

pyramid or machines with complex faults.Benefits of Tiered Maintenance 

• Don’t spend time analyzing healthy machines

• Reduce the number of work orders

• Don’t deploy your experts on simple faults

 

When to use vibration tools?

Input Power Quality

Drive & Drive Output Signals

Motor load / windings

Motor testing / insulation

Mechanical vibration & alignment

Calibrate process controls & variables

Think about your assets holistically: electricity in and work out- Every link in the chain is a potential failure and some links lie outside the physical “machine”

Electrical (scopes, DMM)Thermal (imagers)

Mechanical (vibration)

Oil AnalysisUltrasonic

VibrationElectrical

Thermography

Audible NoiseHot to Touch

Energy Waste

Cost to Repair

• Different assets require a different mix of technologies: Electrical, Thermal, Mechanical

• For rotating machines, vibration is the best tool – ultrasound is too early and thermography is too late

When to use vibration tools?First, screen machines to find out which ones are good or bad

Second, diagnose machine faults and determine repair recommendation

Third, correct the problem

Last step is to check machine to ensure repair is good and return to service

Vibration meter Vibration meter or tester

How is vibration testing performed?Vibration analysis basicsVibration for a moving object can best be illustrated as a sine wave that repeats over and over along the horizontal axis. See below the mass on a spring that generates a sine wave of vibration as it moves up and down over time. One complete sine wave is a cycle. The time it takes for the cycle to repeat is the frequency or speed of the waveform.

The vibration waveform also has an amplitude or magnitude that can be measured in the vertical axis. There are three ways that the waveform’s amplitude can be reported:

Vibration basics on machinesVibration testing on rotating machines provides vital machine condition information. Here are some vibration basics:

If a motor shaft turns the pump shaft at 1776 RPM for example, a heavy spot on the shaft causes an outward force in all radial directions as the shaft turns. This is like a hula hoop. Note: Even a healthy machine will have some vibration as the shaft turns, but this is considered normal.

1776 Revolutions Per Minute (RPM) = 1776 Cycles Per Minute (CPM) (Rotating shaft) (Sine wave)

Vibration basics on machinesThe rotating motor shaft turns the pump shaft through the coupling. • Every time an impeller vane passes the sensor, it creates a small vibration. • If the pump has 10 impeller vanes, the sensor sees vibration from a vane 10 times

for every shaft revolution. • The larger mass of the shaft will cause more vibration amplitude than the impeller. • The sine wave for the pump impeller vibration will be smaller in amplitude than the

shaft vibration, but more cycles (10) for one complete shaft rotation.

10 vibrations per shaft revolution = 10 cycles per shaft revolution(Rotating impeller vanes) (Sine wave)

Complex waveforms

If we superimpose the two sine waves (shaft and pump impeller) it might look like this:

But really the vibrations add to each other and look more like this

And 20 or 30 vibrations from different components of a real rotating machine might look like this

- 1 revolution of shaft- 10 impeller vibrations per 1 shaft rotation

Frequency (spectrum) analysis• The time waveform contains information about the machine, but patterns of

different components are overlapped and jumbled together • A mathematical algorithm (FFT) converts the complex time waveform into a simple

graph called the frequency spectrum. • It separates the individual waveforms so that we can analyze them separately. This

conversion is performed inside the tester.

• From our earlier example, we can see how the complex waveform (above on left) is made up of two separate waveforms (above center) that can then be converted to a spectrum (above on right) which is a simple plot of the signal’s amplitude (y–axis) against frequency (x-axis).

Notice the amplitude of the shaft sine wave (1 cycle) is three units and the amplitude of the pump impeller sine wave (10 cycles) is one unit.

Frequency (spectrum) analysis The same thing is seen in the spectra from a real rotating machine:

– These peaks are at specific frequencies that represent vibrations going on in the machine.

– Machine diagnostics involves matching the peaks in the spectrum with events that exist in the machine

– Spectral analysis is the primary tool we use to diagnose the condition of rotating machines

Overall Vibration (OV) analysisOverall vibration analysis is much simpler, but there is no detail:• From the same vibration data, one single overall vibration value is calculated,

which represents the average energy of the vibration sample. • The meter uses this single value as an indicator of the overall health of the

machine (trend graph) and compares it to standards (ISO 10816-1)• The tester uses this single value to help confirm the diagnostic report to and to

indicate if a problem other than a fault (foundation, resonance) may be present.

Meter Tester

Machine basics for rotating machinesOver 30 years, a team of vibration experts learned that machines really aren’t that different from each other • From a vibration stand-point, most machines are just a couple of shafts with two

bearings each and something in-between connecting the two shafts (a coupling, a belt, or a gearbox).

• The determining factors for a machine that can be diagnosed with an automated vibration tester isn’t size, criticality, or complexity, but rather, whether there are any large and rapidly changing variations in machine conditions: speed, load, etc.

• Most rotating machines are pretty consistent for the time it takes to perform a vibration test and only a few machines require an expert using an advanced vibration analyzer. Refer these machines to a consultant or service provider.

Machine basics for rotating machinesFor vibration testing, we can simplify a machine to one or two shafts with two bearings each and something connecting the shafts. Look at your machine and identify the shaft(s), bearings, coupling, and driven component.

When the motor turns does anything else turn? Is there anything on motor shaft? If yes, then do not select #1. This option is only for stand-alone motors, such as a motor that has been removed, repaired, and sitting on the shop floor or test bench. If anything else is connected to the motor, the diagnosis will be wrong.

1. Motor Detached (no driven)

Machine basics for rotating machines

Does the machine have just two bearings? If no, then do not select #2. See #3.This option is for situations where the pump, compressor, or fan is mounted directly on the motor shaft.

2. Motor Close Coupled with Overhung Driven

3. Motor Coupled with Overhung Driven

This option is for machines with four bearings and two shafts going the same speed. Most machines have some type of flexible element between shafts to allow give.

Machine basics for rotating machines

This option is not very common. It is for machines with four bearings and two shafts going the same speed, but with a solid shaft (no flexible coupling). Most machines are either close coupled (#2) or have a flexible coupling (#3).

4. Motor No Coupling and Supported Driven

This option is for machines with four bearings and two shafts going different speeds. It is very important to identify the speed of both shafts. If possible, finding the belt speed will help eliminate false bearing calls.

5. Motor with belt-drive and overhung driven

Machine basics for rotating machines

This option is for machines with four or more bearings and two shafts going different speeds. It is very important to identify the speed of both shafts. If possible, finding the gear teeth count will help eliminate false bearing calls.

6. Motor, Coupling, Gearbox, Coupling, Driven

This option is not very common. It is for machines with four or more bearings and two reductions (gearbox and belt). It is very important to identify the speed of both shafts and both reductions. Multiple intermediate components like this are very rare.

7. Motor, Coupling, Gearbox, Belt-drive, Driven

Machine basics for rotating machinesWhat is on the inside? Pumps

Centrifugal Propeller Piston

Lobed Sliding vane Screw 

Simple steps to use vibration tools

First step - setup the tool to test the machine

Step two - take measurements from the machine

Step three - diagnose faults and decide if action is needed

Ana

lyze

r

Test

er

M

eter Only need to

know machine name and type

Fast, 1 second test in 1 direction only on 1 or 2 bearings of machine

Screen health of machine in seconds => good or need further testing by tester

Quick setup using machine setup wizard – basic information that technician knows

3 (simultaneous) axis of high-resolution data takes < 1 minute on 3 or 4 bearings of the machine

Diagnoses most common machine faults automatically in < 5 minutes and provides severity with repair recommendation

Analyst needed with deep understanding of vibration to select optimal frequency ranges and setup complex program

Detailed analysis by an expert for complex faults or complex machines – in 30-40 minutes

3 (1 at a time) axis of high-resolution data takes 1-2 minutes on each of 3-4+ bearings of the machine

Training series

Simple Steps to use the Vibration Meter

Training is a key ingredient to program success

Vibration meter – overall vibration• Mechanical vibration is a notoriously difficult subject matter to master• The vibration meter yields significant benefits without requiring advanced training

by end-users• All vibration data is collected in the time domain from a piezoelectric accelerometer.• The time domain data is used to calculate one single overall vibration value that

can be used as an indicator of the overall health of the machine and can be trended over time. This number is like an average of all of the energy.

0.20 in/secOverall

Time domain data Overall Vibration (OV) Trend plot

Vibration meter – Overall Vibration (OV)Three limitations of overall vibration and the solutions:1. Different machine types have different healthy levels of overall vibration Solution – use a database of different OV levels for 37 machine categories2. Bearing flaws will not cause an alarm in OV until significant damage occurs. Solution – use high frequency Crest Factor + to detect the impacting of bearings3. A severe level of OV does not identify the root cause fault of the machine Solution – trend the OV and use a vibration tester to diagnose the fault

Crest Factor +• A limitation of overall vibration analysis is bearing flaws will not cause an

alarm until significant damage has occurred• Crest Factor looks in the high frequency for bearing impacting• Crest Factor Plus is a proprietary weighted calculation that is a significant

step forward from traditional crest factor vibration analysis because the output value (CF+) increases continually as the bearing damage worsens

Vibration meter – Crest Factor (CF+)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct02468

101214

CFCF +

26

Vibration meter – overview

Rugged - made of tough, heavy plastic. Feels solid and well-balanced in your hand.

Green light indicating right amount of pressure is applied (wait 3 seconds after pressing Measure button taking a measurement)

Three measurements: overall vibration, bearing condition and temperature reliably

Two severity levels: Four-level severity scale both overall vibration and bearing condition using textual alerts (Good, Satisfactory, Unsatisfactory, Unacceptable)

A combination force sensor tip and vibration sensor compensates for user variance (force or angle) yielding in accurate, repeatable readings.

Tip is specially designed to get both low frequency (OV) and high frequency (CF+) measurements.

How to Setup your machine – just once

STEP 1 – SETUP : Press the grey “Setup” button1. Use the arrows to select “Create NEW setup”, Press “Enter”.2. Use arrows to scroll through 37 predefined machine categories.

Select “Horiz Centrif – Single Suction” pump (for both pump & motor)3. Motor 1800 RPM => Select RPM Range > 600 RPM, press “Enter”.4. Enter machine name - use arrows to move from one character to next.

Push “Enter” button to confirm. To delete characters, push “Back”. When name complete (TW Pump 3), Press “Save”

1 2 3 4

Compares data to real data baselines from 37 machine types:

Vibration meter – where to measureLocate the sensor tip as close as possible to the bearing, or on a solid structural member leading to the bearing

How to Screen Machine ConditionINTERPRETATION OF MEAUREMENTSeverity scale gives a better understanding of the overall vibration and bearings.

CF+ Scale (Bearing health): 0 - 5 = Good6 -10 = Satisfactory11-15 = Unsatisfactory16 & > =Unacceptable

Overall Scale (Machine health):Depends on machine type (which of the 37 machine categories did you select?)

Store Data to Excel template

X-Axis on bottom = time Y-Axis on left = OV-Velocity (Light blue plot trending up) Sec-Y on right = CF+ (Dark blue plot at zero)

Vibration meter - ISO Standard

10816-1: General guidelines machine vibration measurements on non-rotating parts

1. Class 1 – Engines and integrated machines2. Class 2 – Medium-sized machines (15 -75 kW output)3. Class 3 – Large machines on rigid, heavy foundations4. Class 4 – Large machines on soft foundations

10816-3: Industrial machines with nominal power above 15 kW and nominal speeds between 120 RPM and 15,000 RPM when measured in situ

5. Group 1 – Large machines > 300 KW and < 50 MW6. Group 2 – Medium-sized machines > 15 kW and <=

300 kW10816-7: Rotor dynamic pumps by measurements on nonrotating parts

7. Category I – Pumps with a high level of reliability and safety

8. Category II – Pumps for general or less critical applications

Excel template Overall Vibration Severity refers to one of three ISO Standards:

Vibration meter – save to the cloud

External Sensor – how to use1. Find a short & solid transmission path from the rotating shaft to a bearing and wipe the metal surface with a rag to remove dirt and grease.2. Locate the sensor securely on a solid, bare, metal surface of the bearing housing (not on a thin cover).3. Roll the sensor when using a magnet mount to prevent damage to the crystal and check magnet has a good grip.4. Ensure the measurement is taken under normal operating conditions.

Training series

Simple Steps to use the Vibration Tester

Training is a key ingredient to program success

Vibration tester - overview

Three easy steps to get machine condition answers

Vibration tester - Setup machineHow to answer the setup questions for a vibration test To accurately diagnose a wide range of machine conditions, the 810 needs a complete and accurate description of the components being tested and how they are configured. This machine setup information tells the 810 software where normal vibration peaks should be expected.

To gather the required information quickly and conveniently, the Tester asks a series of questions about the following topics when you set up a new test:• Motor that drives the system• Couplings and transmission• Driven component

As you answer these questions, the Fluke 810 Vibration Tester displays an image of the system that you have described so you can be sure that it is accurately represented.

HINTS AND TIPSSome complex machines can be treated as if they are just two or more standard machines combined.

Different ways to find speed for a shaft 1. Laser tachometer

• Need to stop machine and attach reflective tape• Very accurate and easy to use (Spikes Per Minute = RPM)• See operation during the 810 Measure video (later)• Preferred method but not always convenient

2. Contact tachometer • No need to stop machine to attach reflective tape• Not always the best method – limited access & safety concerns• Need to have physical contact with rotating component• No limit of shaft speed or lighting conditions (like stroboscope)

3. Stroboscope • No need to stop machine to attach reflective tape• Best method unless shaft speed is very low (< 500 RPM)• See operation on next slide• FPM (Flash Per Minute) = RPM

4. Display on the variable frequency drive (just do some quick math – it doesn’t have to be exact, just in the ball park) VFD % X motor nameplate speed5. Use the 810 to find the speed (just setup a test for a small stand-alone motor) Take one measurement from the motor bearing, Diagnose, and find 1X peak (biggest peak). The speed of the peak will be shown in Cycles Per Minute (RPM).

Why a stroboscope is needed• Quickly “freeze” fast-moving machines or processes to observe or identify without having to shut-down the operation — Is the speed correct? Is something wrong?• LED Stroboscopes are rugged and easy to use tools to troubleshoot and inspect machines without contact and without stopping production (take in your tool bag). • Read RPM on display and manually enter speed into the Vibration Tester

 Common uses for the stroboscope:• Turbines vary in speed and change speed frequently• VFD motors vary in speed, but do not change frequently• Visually inspect fast moving parts for problems without shutdown • Find belt rotation speed and look for belt slippage (compare pulley speeds) • Find machine element components and part numbers – fan blades, pump

vanes, compressor screws, gear teeth, etc. without shutting down• Inspect leading edge damage and material buildup on fan blades • Investigate repetitive moving processes for flaws, timing problems, or

misfires

 Hundreds of industrial uses and applications:• Electronics/electrical engineering• Shipbuilding, aircraft construction• Food & beverage, manufacturing

•  Print, paper, cardboard manufacturing• Optics manufacturing• Machine construction

Vibration tester: Setup machine – follow steps of wizard

What if you don’t know the answer to a Setup question?Many answers can be assumed. Some answers can be left blank.Some answers are critical to achieve an accurate diagnosis.If in doubt: Some entries can be assumed without sacrificing accuracy. Example: If in doubt, select roller bearings. Optional: Some entries can be left blank at the beginning, but should be updated later when the information is found. Some missing information can lead to misdiagnosis. Important: All other items are critical and need to be filled in or the accuracy of the diagnosis may be in question.

Journal bearings include any bearing without rolling elements: sleeve, journal, Babbitt, etc. and use soft metal and sometimes an oil bath instead of rolling elements.

Roller bearings include any bearing with rolling elements: balls, cones, tapered roller, etc. and have a different wear pattern than journal bearings.

CAUTION

Vibration tester - Measure machine1. Vibration transmits down the

shaft, through the bearing, into the bearing housing, into the sensor magnet and into the sensor.

2. The triaxial sensor measures vibrations in all three directions simultaneously.

3. The sensor converts vibrations to an electrical signal and transmits it to the tester

Where to mount the sensor? For vibration testing, we can simplify things to a simple shaft with two bearings. Look at your machine and identify the shaft, bearings, coupling, and driven element. Then mount the triaxial sensor on the bearing housing or as close to the bearing as possible

Measure machine – sensor mounting

Where to mount the sensor? It is really quite simple: mount the sensor on solid metal anywhere on or near the bearings but not on thin covers

Measure machine – mounting examplesMotor close coupled (single shaft) machines Don’t measure from pump housing or middle of motor. Measure from bearing housing.Vibration from impeller will transmit to bearing #2. Vibration from bearing #1 will transmit to bearing #2. If motor is small (40HP or less), collect data from motor bearing #2. If large, collect data from both bearings Not a bearing or a coupling.

Seals keep water in the pump from entering the motor. Do NOT measure from here.

On motors without a cooling fan, it is OK to mount the sensor on the end of the motor as long as the metal is solid.

No bearings on pump. Do Not measure from pump. You will only see flow noise. Only measure from bearings.

Easy measurement – follow screen icons1

2

3Press Diagnose then review4

Select location on machine – sensor location number

Select orientation on the machine – sensor located on bearing in relation to shaft

Select orientation of sensor – is the sensor cable perpendicular or aligned with the shaft

Vibration analyzer – manual analysisVibration analysis can be simplified to a three-step process:

1. Identify vibration peaks as they relate to a source component on the machine.

2. Look for patterns in the data based on vibration rules.

3. Measure the amplitude of the vibration peak to determine the severity of the fault

Once the fault and severity are determined, a repair can be recommended and a work order generated. There are hundreds of faults, but most are infrequent or rarely seen. Instead of learning hundreds of rare faults, learn the four most common machine faults that you will find every day and are easy to correct:

1. Imbalance2. Misalignment3. Looseness4. Bearing Failures

Vibration tester – automated analysisAutomated machine diagnostics of the vibration testerTurns vibration data into machine condition answers:

Quick, easy, and proven accurate:1. Easy setup – Machine wizard uses default settings to help the user2. Complete measurement – Icon-driven menus and triaxial sensor3. Reliable diagnosis – Proven program modeled after expert analysis4. Review final results – Review the data and setup on the Viewer software5. Make repairs – Measure again to check work and verify the before/after conditionFeel confident about the severity of your machine faults and repair recommendations by reviewing and validating the vibration data yourself.

Vibration tester - review the reportReview the machine condition report and then decide what action is needed:.

Name of machine testedBearing locations measured (notice only 3 of the 4 locations were tested)Reference data to verify valid measurement and identify other possible concernsFaults, Severity, Severity Score (1-100) , Severity Scale (green-yellow-orange-red)Recommendations, Priority, Priority Description

• Start small and grow show success get more budget to grow. The #1 killer of a new program is starting too big. You are still setting up hundreds of machines, but results are expected now, so someone at the top will pull the plug on the resources. A smarter method is to start with 25-50 assets (under the radar of top management) and get a few successes. Then wave the flag to let everyone know that reliability is paying off in a big way. This is a better recipe for success than trying to change company culture overnight.

• Start with simple machines at the beginning and focus on problem machines. Add tough machines as your training and experience grows.

Start-up a successful vibration program:Program Pillar #1 – new program start-up

Example Criticality List (Excel) Example Asset Test Schedule (Excel)

• Use automation and proven measurement methodology to get a complete picture of the machine’s entire power train.

• The #1 killer is choose one maintenance technology and just measure everything you can. Maintenance technicians and operators don’t have time to look over reams of data—they have a plant to run. The goal should be a system that screens the data and provides answers about what is wrong with a machine and what to do to fix it.

• A better method is to focus on the likely failure modes, and match the right maintenance technologies to the most likely failure mode.

Start-up a successful vibration program:Program Pillar #2 – Technology selection

Pillar 3 – Database management• #1 killer of an existing program is data overload – what to do with all of the

new data? Unless data is converted to machine condition answers then the program is doomed to fail. The real power of Tiered Maintenance is unlocked when the advanced tools from multiple technologies have the ability to transfer measurements to a single database that allows everyone on the team to collaborate in real time and flag or escalate issues up the tiers.

• Team members need access to full measurements history on a given machine from anywhere in the field or on the plant floor or from home.

Why a vibration meter is needed• Screening and repairing machines only when they fail decreases production revenue while increasing energy waste and maintenance costs • Seeing early warnings of impending machine failure empowers maintenance staff time to schedule repairs

Just like a nurse that takes your vital signs before you see the doctor, the vibration meter screens your machine with 3 simple tests to check its health

It has a built-in database of overall vibration levels from years of analyzing thousands of real machine

External Sensor - allows technicians to get into tight places to take vibration measurements where the stinger probe doesn’t otherwise fit.

Answers not just data – Five tools in one:1. Bearing health— 4 level severity score: good or bad 2. Bearing impact— high frequency vibration plus trending3. Overall machine health— 4 level severity score: good or

bad compared to real data from 37 machine categories 4. Overall vibration— low frequency vibration plus trending 5. Temperature— Infrared temperature of bearing surface

Built with

FLUKE CONNECT

Why a vibration tester is neededA simple three step process provides machine condition answers without difficult analysis. • Repairing machines only when they fail decreases production revenue while increasing energy waste and maintenance costs. • Seeing early warnings of impending machine failure empowers maintenance staff time to schedule repairs. • Most machine failures come from four common faults: imbalance, misalignment, bearings and looseness.

Just like a doctor that diagnoses most problems without the need to see a specialist—90 % of machines are standard motors, pumps, fans, compressors, blowers, gears, belts that have very few variables.

 Reduce training costs: • Easier and faster measurement using the triaxial sensor • Automated built-in expert diagnostic engine • Extensive setup, trending, analysis, on-site expert not needed to get machine answers • Training is the key to a successful proactive maintenance program — easy to learn the steps to review diagnostic results

The vibration tester has a proven auto diagnostic program based on 30 years of machine baselines to analyze machines for you and get you back to work.

Click to edit Master title style

Questions or Comments?Email Nicole VanWert-Quinzi nicole.vanwert@Transcat.com

Transcat: 800-800-5001www.Transcat.com

For related product information, go to: www.Transcat.com/Megger