The information provided by this tool is based on current best practice in ultrasound-based condition monitoring. It supports informed decision-making and should be treated as a professional recommendation. It does not replace the judgement of a qualified engineer, manufacturer specifications, or site-specific procedures. RFL Training accepts no liability for decisions made solely on the basis of this tool.
Before you begin
Read this once. It will make every inspection better.
This matrix supports your determination — it does not make it for you. You are the instrument. Your ears, your judgement, and your knowledge of the asset are the primary diagnostic tools. The matrix provides structure, guides your thinking, and produces a document that supports your finding. If you are uncertain, run the matrix again with different CI inputs and compare the outcomes. That is not weakness — that is good diagnostic practice.
Accurate shaft speed is not optional. Every X multiple calculation in Gate 2b depends on it. An incorrect speed produces incorrect bearing frequency classifications — a bearing fault can look mechanical, and a mechanical source can look like a bearing. If the speed is unknown, use a tachometer before collecting. Do not guess.
dBµV Calculator
Convert between decibel microvolts and linear microvolts, or compare two readings to see the linear change.
dBµV
µV (linear)
Previous reading (dBµV)
Current reading (dBµV)
RFL Steelman Matrix
Select a pillar to begin.
Pillar 1 — Mechanical Condition Monitoring
Bearings, pumps, motors, couplings, fans, rolls
Pillar 2 — Lubrication Replenishment Observations
Null return report · Recurring observation report
PILLAR 2 · LRO
Lubrication Replenishment Observations
Select the type of observation to record.
Null return — unchanged condition
The bearing did not respond to greasing. Signal unchanged. Generates findings sheet and DIS sheet for the planner.
Recurring observation
This asset behaves abnormally during lubrication replenishment over multiple visits. Generates a recurring observation report.
Enter asset details if available. Fields are optional — required only to submit a formal finding.
Asset ID optional
Tech name optional
Turning speed optional
Date auto
Asset configuration
Motor / Coupling / Pump
Standard configuration
Build your own
Non-standard drivetrain
Drive type
Driven shaft speed speed of the driven machine, not the motor
Is this motor VFD driven?
VFD noted. Carrier frequency whine may appear in the time waveform — normal. Crest Factor and time waveform remain primary diagnostic tools regardless of speed variation.
Mechanical Condition Monitoring → Select measurement point
Select measurement point
Click where you are investigating. Energy flows left to right.
Bearing type
Gate 1 of 3
Waveform consistency
Open your waveform in UAS®. Enter RMS and MaxRMS if available.
RMS (dBµV) optional
MaxRMS (dBµV) optional
Consistent
Stable amplitude throughout the sample.
Inconsistent
Amplitude changes dramatically mid-sample.
Does the amplitude change dramatically from beginning to end?
Gate 2 of 3
Acoustic assessment
The asset announces itself. Your ears are the first filter.
UAS® always marks the 10 highest peaks. Always. If you did not hear anything — in the field or on playback — those peaks are the tallest blades of grass. Do not go looking for a problem. Let the sound tell you there is one.
During collection or on UAS® playback — did you hear repetitive events?
Play the time waveform in UAS®. Listen. Did something announce itself?
Confirm visually — zoom into the time waveform
Your ears heard something. Now look at the waveform. Are the events visible?
Classify the character of the events
Gate 2b — Peak Classification
Classify the frequency
Discrete impacts confirmed. Identify the frequency of the repeating event before assessing CI trends.
3X running speed is NEVER a bearing. 3.243X is a strong indication of one. Exact integers are mechanical. Non-integers in the 0.35–12X range are bearing candidates.
Speed not provided. Running speed is required to calculate X multiples and apply the bearing frequency filters. Go back to Screen 1 and enter the turning speed before proceeding.
How are you identifying the harmonic frequency?
Choose your input method. FFT cursor read is primary.
Harmonic frequency (Hz)
Impact count
Sample length (seconds)
Time between peaks (seconds)
Gate 3 of 3
CI assessment
Open the static trend screen in UAS. Look at what the trend lines are doing — not what the numbers are.
RMS value alone is never a determination. What matters is trend over time and whether RMS and Peak are moving together or diverging.
RMS trend
What is your RMS line doing over the last several readings?
Peak trend
What is your Peak line doing relative to RMS?
Crest Factor trend
The ratio of Peak to RMS. Does not change with speed. The earliest warning indicator.
Gate 2 — Volute Acoustic Assessment
Acoustic assessment
The volute announces its condition. What did you hear?
Cavitation sounds like popping, crackling, gravel, or static — NOT grinding. Vapor bubble collapse at the impeller. If you hear this, the fix is a process change, not a wrench.
What did you hear at the volute?
In the field or on UAS® playback.
Gate 2b — Volute Frequency Classification
Classify the frequency
Repetitive impacts confirmed at the volute. Identify the frequency.
At the volute, integer multiples of running speed (3X, 4X, 5X) indicate impeller rubbing on the volute casing. This is a clearance issue — worn wear rings or severe off-BEP operation. Report to operations and planner.
Speed not provided. Running speed is required to calculate X multiples. Go back to Screen 1 and enter the turning speed before proceeding.
How are you identifying the harmonic frequency?
Harmonic frequency (Hz)
Impact count
Sample length (seconds)
Time between peaks (seconds)
Gate 3 — Volute RMS Trend
RMS trend assessment
Open the static trend screen in UAS. What is the RMS line doing?
At the volute, RMS reflects turbulence at the impeller. The further from BEP the pump is operating, the more turbulence — and the higher the RMS. A rising trend means conditions are getting worse. Report to operations.
Coupling gate
Coupling acoustic assessment
Couplings are assessed by airborne sound only — structure-borne transmission is unreliable at the coupling point. Your ears and playback are the tools.
Ultrasound at a coupling point captures airborne only. Do not assess CI trend data at the coupling — the signal is dominated by adjacent bearings. Acoustic queue is the sole diagnostic tool here.
During collection or on UAS® playback — did you hear repetitive events?
Play the time waveform in UAS®. Listen. Did something announce itself?
Confirm visually — zoom into the time waveform
Your ears heard something. Now look at the waveform. Are the events visible?
Classify the character of the events
Mechanical Condition Monitoring → Determination
Findings summary
Review your findings. Select the determination that the evidence supports.
No evidence of fault — continue routine monitoring exam aligned
No acoustic events. All CI indicators stable. No evidence supports intervention.
Evidence of developing condition — action required exam aligned
One or more gates returned a significant finding. Evidence for a developing condition is stronger than evidence for healthy.
Insufficient data — validate before acting exam aligned
Significant N/A answers, single anomalous reading, or conflicting indicators. More information needed.
Select recommended action
Supporting notes optional
Mechanical Condition Monitoring → Finding summary
Finding summary
Review your finding below. Print or copy to record it.
Notes
Attach DIS sheet
Print both documents below and staple together before sending to the planner.
BYO — Drivetrain builder
Mechanical Condition Monitoring → Build your own drivetrain
Step 1 — Build your drivetrain
Add components in order, left to right. Energy flows motor → load. When the chain is complete, proceed to configure bearings.