How to Build Reliable Vibration Trends Before Predictive Maintenance Malaysia

Predictive maintenance does not begin with artificial intelligence.

It begins with reliable, repeatable vibration measurements.

If a factory collects readings from different positions, under different operating loads or using inconsistent measurement settings, the resulting trend may show changes that are unrelated to the actual machine condition.

Before investing in automatic diagnosis or AI-based maintenance software, factories in Malaysia should establish a disciplined vibration monitoring programme.

What Is a Vibration Trend?

A vibration trend shows how a machine’s measured vibration changes over time.

Instead of judging the equipment from one reading, the maintenance team records measurements at regular intervals and compares them with:

• The original baseline

• Previous readings

• Similar machines

• Maintenance history

• Operating conditions

• Established alarm levels

A rising trend may indicate that the machine condition is changing.

However, the trend is useful only when the readings are technically comparable.

Why Is One Vibration Reading Not Enough?

A single vibration value is only a snapshot of the machine at that moment.

The reading may be influenced by:

• Operating speed

• Mechanical load

• Production rate

• Temperature

• Flow condition

• Lubrication condition

• Nearby machinery

• Sensor position

• Measurement direction

• Instrument settings

A high reading does not automatically confirm a bearing fault.

Likewise, a low reading does not guarantee that the machine is free from developing problems.

Trend monitoring helps the maintenance team recognise gradual changes that may not be obvious from one inspection.

Step 1 – Identify the Machines That Matter Most

Do not begin by measuring every machine in the factory.

First, identify equipment where failure would create the greatest operational impact.

Priority equipment may include:

• Production motors

• Pumps

• Fans and blowers

• Compressors

• Gearboxes

• Cooling-tower equipment

• Chillers

• Conveyor drives

• Extraction systems

• Critical utility machinery

Consider:

• Safety risk

• Production downtime

• Repair cost

• Spare-part availability

• Replacement lead time

• Environmental impact

• Effect on product quality

A smaller, well-managed monitoring programme is more useful than collecting inconsistent data from hundreds of machines.

Step 2 – Create a Machine Register

Assign each monitored machine a clear identification.

The register may include:

• Machine name

• Asset number

• Department or location

• Motor power

• Operating speed

• Bearing type, if known

• Driven equipment

• Installation date

• Maintenance history

• Criticality level

• Normal operating condition

Use the same asset identification on the measurement sheet, maintenance report and vibration trend.

This prevents readings from being assigned to the wrong machine.

Step 3 – Select Permanent Measurement Points

The measurement point must remain consistent from one inspection to the next.

Typical locations may include:

• Motor drive-end bearing

• Motor non-drive-end bearing

• Pump bearing housing

• Fan bearing housing

• Gearbox input

• Gearbox output

• Driven-machine bearing

• Structural support near the bearing

Choose points that:

• Are close to the bearing or vibration source

• Provide solid mechanical contact

• Can be accessed safely

• Can be located again

• Are not on a loose cover

• Are not affected by thin sheet metal

• Are suitable for the selected probe or sensor

Mark each point using paint, a label, a photograph or a measurement-point tag.

Measuring “somewhere near the motor” each month will not produce a reliable trend.

Step 4 – Define the Measurement Direction

Machine vibration may be measured in different directions:

• Horizontal

• Vertical

• Axial

Each direction may respond differently to a mechanical problem.

For example, a machine may show a stronger change in one direction because of its mounting, shaft alignment or structural stiffness.

The maintenance route should define exactly which directions are required at each point.

Do not compare a horizontal reading taken last month with a vertical reading taken this month.

Step 5 – Record the Operating Condition

Measurements should be collected under comparable machine conditions.

Record information such as:

• Running speed

• Production load

• Flow rate

• Valve position

• Process condition

• Product being processed

• Machine temperature

• Start-up or steady operation

• Number of machines operating nearby

For variable-speed equipment, record the actual speed during every inspection.

If the machine is measured at 1,500 RPM during one visit and 900 RPM during another, the difference may reflect operating speed rather than mechanical deterioration.

Where practical, define a standard operating condition for routine trend measurements.

Step 6 – Select the Correct Vibration Parameter

Different vibration parameters provide different information.

Depending on the instrument and application, measurements may include:

• Acceleration

• Velocity

• Displacement

• RMS value

• Peak value

• Crest factor

• Frequency spectrum

• Bearing-condition indicators

The chosen parameter should match the machine, expected fault and monitoring objective.

A general overall vibration reading may be useful for routine screening.

Early bearing problems or complex machinery may require suitable high-frequency measurements, waveform analysis or frequency-spectrum analysis.

Do not compare results collected using different parameters or engineering units as if they were identical.

Step 7 – Use the Same Instrument Settings

Before collecting trend data, standardise the instrument configuration.

Confirm:

• Measurement parameter

• Engineering unit

• Frequency range

• Filter setting

• Measurement range

• Averaging method

• Measurement duration

• Sensor sensitivity

• Data-storage format

A change in filter or frequency range can produce a different overall value even when the machine condition has not changed.

Record any unavoidable setting change and avoid joining incompatible readings into one continuous trend.

Step 8 – Use Consistent Sensor Mounting

Sensor mounting has a major effect on vibration measurement.

Possible methods include:

• Handheld probe

• Magnetic base

• Stud mounting

• Adhesive mounting

• Permanently installed sensor

A handheld probe may be appropriate for basic route-based checks, but the operator must use consistent position, direction and pressure.

A magnetic or fixed mounting method may improve repeatability where the machine surface and application allow it.

Do not compare readings collected using substantially different mounting methods without considering their frequency response and measurement behaviour.

Step 9 – Establish the Initial Baseline

A baseline represents the machine under a known operating condition.

Where possible, establish the baseline when:

• The machine is believed to be in acceptable condition

• Bearings are known to be serviceable

• Alignment has been checked

• Lubrication is correct

• Mounting bolts are secure

• Normal load and speed are available

Collect more than one measurement.

A single baseline value may be affected by a temporary process condition or operator error.

The initial record should include:

• Overall vibration values

• Measurement directions

• Machine speed and load

• Instrument and settings

• Date and operator

• Temperature where relevant

• Maintenance condition

• Spectrum or waveform if required

After major repair, motor replacement, alignment or balancing, establish a new reference and retain the previous history.

Step 10 – Choose an Appropriate Inspection Interval

The measurement frequency depends on machine criticality and how quickly a fault could develop.

Possible intervals include:

• Daily

• Weekly

• Monthly

• Quarterly

• Before and after maintenance

• After an abnormal event

Critical or fast-running equipment may require more frequent checks than non-critical standby machinery.

A machine showing a rising trend may also require shorter measurement intervals.

Do not select an interval only because it is convenient. Consider the machine risk, operating hours and possible failure-development period.

Step 11 – Take More Than One Reading

Before accepting a value, repeat the measurement.

Check whether the result is stable.

If readings vary significantly, investigate:

• Probe position

• Sensor mounting

• Surface condition

• Machine speed

• Load changes

• Nearby machine activity

• Instrument range

• Loose guards or covers

Do not average several poor-quality readings and assume the result is reliable.

First confirm that the measurement process is stable.

Step 12 – Record Maintenance Events

A trend is easier to understand when maintenance history is shown alongside the vibration data.

Record events such as:

• Bearing replacement

• Lubrication

• Alignment

• Balancing

• Foundation repair

• Bolt tightening

• Coupling replacement

• Impeller cleaning

• Belt adjustment

• Motor replacement

• Process change

After maintenance, check whether the vibration returns towards the earlier baseline.

If vibration increases after a repair, review the installation and operating condition before assuming that the new component is defective.

Step 13 – Investigate Sudden and Gradual Changes Differently

A gradual increase may indicate progressive deterioration.

Possible causes include:

• Bearing wear

• Lubrication degradation

• Increasing imbalance

• Coupling deterioration

• Foundation movement

• Progressive looseness

A sudden increase may be caused by:

• Component failure

• Impact

• Loose mounting

• Process change

• Foreign material

• Sensor-placement error

• Operating-speed change

• Maintenance activity

The trend shape provides useful context, but further checks are still required to identify the cause.

Step 14 – Use Alarm Levels Carefully

A monitoring programme may use more than one action level.

Advisory Level

Possible action:

• Repeat the measurement

• Confirm the operating condition

• Check the measurement point

• Compare with previous readings

• Increase monitoring frequency

Warning Level

Possible action:

• Conduct additional vibration analysis

• Inspect lubrication and mounting

• Check alignment or balance

• Plan maintenance

• Compare temperature and process data

Critical Level

Possible action:

• Follow the factory’s approved escalation procedure

• Assess operating risk

• Notify responsible personnel

• Conduct immediate inspection

• Decide whether the machine can continue operating safely

Alarm limits should consider the machine type, project or company requirements, historical behaviour and engineering assessment.

Do not set the critical alarm simply by adding a small percentage to one baseline reading.

Step 15 – Review the Frequency Content When Necessary

Two machines can have similar overall vibration values but different underlying problems.

Frequency analysis may help distinguish between conditions such as:

• Imbalance

• Misalignment

• Mechanical looseness

• Bearing-related activity

• Gear-related vibration

• Electrical influence

• Resonance

A handheld overall vibration meter may identify which machine deserves attention.

A spectrum-capable instrument or more advanced monitoring system may then be required for deeper diagnosis.

Overall vibration trending and frequency analysis are complementary—not interchangeable.

Step 16 – Check the Data Before Using AI

Before feeding historical vibration data into an AI platform, review the dataset for:

• Missing readings

• Wrong machine identification

• Mixed measurement directions

• Different engineering units

• Changed sensor locations

• Instrument-setting changes

• Different operating speeds

• Maintenance events

• Obvious measurement errors

• Long periods with no data

Poor-quality historical data may teach the system the wrong patterns.

AI can process large datasets, but it cannot automatically restore information that was never recorded correctly.

Portable Instruments for Route-Based Monitoring

Portable vibration meters can be practical for factories beginning a condition-monitoring programme.

Depending on the selected model and measurement requirement, instruments such as the Landtek VM6310, VM6360, Benetech GM63B, Wintact WT63A/WT63B and Smart Sensor AR63B may be considered for suitable vibration screening and trend checks.

Before selection, confirm:

• Required parameter

• Frequency range

• Measurement range

• Sensor arrangement

• Data-recording needs

• Machine type

• Operator experience

Do not select a vibration meter only by comparing price or display resolution.

The instrument must be suitable for the intended machine and fault-detection objective.

When Is Permanent Monitoring More Suitable?

Permanent sensors may be justified when the machine is:

• Highly critical

• Difficult or unsafe to access

• Operating continuously

• Subject to fast-developing faults

• Located remotely

• Required to generate automatic alarms

• Part of a predictive-maintenance programme

Permanent monitoring can provide more frequent data than manual inspection.

However, it still requires proper sensor installation, baseline development, alarm management and data review.

Installing more sensors does not automatically create a reliable predictive-maintenance system.

Daily or Route-Based Vibration Checklist

Before accepting the measurement, confirm:

• Correct machine was identified

• Correct measurement point was used

• Direction was correct

• Operating speed and load were recorded

• Instrument settings were unchanged

• Sensor contact was stable

• Reading was repeated

• Abnormal machine conditions were noted

• Maintenance events were recorded

• Data was saved under the correct asset

This simple discipline improves the quality of the vibration trend significantly.

Common Trend-Monitoring Mistakes

Measuring Different Locations Each Time

The readings may reflect structural differences rather than machine deterioration.

Ignoring Machine Speed and Load

Operating-condition changes may appear as false trends.

Using Different Units

Acceleration, velocity and displacement values cannot be joined directly into one trend.

Changing Instruments Without Cross-Checking

Different sensors or settings may produce a step change in the data.

Recording Only Abnormal Readings

Normal data is required to establish the baseline and understand variation.

Replacing a Bearing Based on One Reading

The result should be repeated and supported by additional inspection where required.

Collecting Data Without Reviewing It

A database has little value if developing trends are not identified and investigated.

Need Help Selecting Vibration Monitoring Equipment in Malaysia?

Send MTM Precision:

• Machine type

• Equipment photographs

• Motor speed and power

• Measurement objective

• Existing vibration readings

• Required parameters

• Number of machines

• Planned inspection interval

• Data-logging requirement

• Whether spectrum or continuous monitoring is required

This information helps determine whether the application requires a basic handheld vibration meter, data-logging instrument, spectrum-capable analyser or permanent monitoring system.

MTM Precision supplies vibration measurement instruments for factories, maintenance teams and contractors in Selangor, Kuala Lumpur, Johor, Penang and throughout Malaysia.

MTM Precision Sdn Bhd
Showroom & Service Centre: No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my