CVA Bearing Analysis & Fault Detection 2

Question 1

What is the crest factor of a vibration signal?

Accepted Answer

The ratio of peak amplitude to RMS amplitude

Answer

The ratio of RMS amplitude to average amplitude

Answer

The ratio of peak-to-peak amplitude to RMS amplitude

Answer

The ratio of velocity RMS to acceleration peak

Question 2

What does a 'sideband' pattern around BPFI indicate in bearing diagnostics?

Accepted Answer

Modulation of the inner race defect frequency by shaft speed, confirming an inner race defect

Answer

Random impulsive noise from bearing contamination

Answer

Cage damage causing amplitude modulation at FTF

Answer

Resonance of the inner race natural frequency

Question 3

What is the ISO 10816 standard's primary concern regarding bearing vibration?

Accepted Answer

Setting velocity-based vibration severity limits for overall machine vibration assessment

Answer

Defining bearing defect frequency calculation formulas

Answer

Specifying accelerometer mounting requirements for bearing measurements

Answer

Establishing bearing life rating (L10) calculation methods

Question 4

What is the Spike Energy (gSE) measurement, and what makes it useful for bearing analysis?

Accepted Answer

A high-frequency (5–50 kHz) energy measurement sensitive to very early-stage impacting from bearing and gear defects

Answer

An overall RMS measurement in the 10–1000 Hz range used for general machinery trending

Answer

A peak displacement measurement used to detect shaft bow in slow-speed machines

Answer

A phase-referenced measurement used to locate the angular position of bearing defects

Question 5

In which bearing failure stage would you expect to see harmonics of bearing defect frequencies clearly visible in the low-frequency velocity spectrum?

Accepted Answer

Stage 3 (intermediate)

Answer

Stage 1 (very early)

Answer

Stage 2 (early)

Answer

Stage 4 (advanced, near failure)

Question 6

What type of bearing fault is indicated by a non-synchronous frequency at approximately 0.4–0.5× shaft speed with harmonics?

Accepted Answer

Cage defect (FTF harmonics)

Answer

Inner race defect (BPFI)

Answer

Rolling element defect (BSF and harmonics)

Answer

Outer race defect (BPFO)