CRE Equipment and Tools Knowledge 2

Question 1

Which condition monitoring technique is MOST effective for detecting early-stage bearing defects in rotating machinery?

Accepted Answer

Vibration spectrum analysis

Answer

Infrared thermography

Answer

Oil pressure gauging

Answer

Visual inspection

Question 2

A laser shaft alignment tool reports an angular misalignment of 0.8 mrad. This value primarily affects which failure mode?

Accepted Answer

Coupling and bearing wear from bending loads

Answer

Corrosion fatigue

Answer

Cavitation in seals

Answer

Thermal expansion cracking

Question 3

When using an ultrasonic thickness gauge, the measured value is lower than the nominal wall thickness. What is the MOST likely cause?

Accepted Answer

Internal corrosion or erosion reducing wall thickness

Answer

Excessive lubrication on the probe

Answer

Probe frequency too high

Answer

Surface roughness on the outside

Question 4

In oil analysis, a high ISO cleanliness code (e.g., 22/20/17) compared to the target (16/14/11) indicates:

Accepted Answer

Excessive particulate contamination requiring filtration or oil change

Answer

Oil is within acceptable contamination limits

Answer

Water contamination only

Answer

Additive depletion without particulates

Question 5

A motor current signature analysis (MCSA) tool detects sidebands at frequencies of line frequency ± 2sf. What does this pattern indicate?

Accepted Answer

Broken rotor bars

Answer

Voltage unbalance

Answer

Stator winding short

Answer

Overloading

Question 6

Which NDT method is BEST suited for detecting surface and near-surface cracks in ferromagnetic components without removing coatings?

Accepted Answer

Eddy current testing (ECT)

Answer

Radiographic testing (RT)

Answer

Magnetic particle inspection (MPI)

Answer

Dye penetrant testing (DPT)

Question 7

A vibration analyzer shows a dominant peak at exactly 1× running speed that increases significantly when the rotor speed changes. The MOST likely cause is:

Accepted Answer

Rotor imbalance

Answer

Bearing outer race defect

Answer

Looseness

Answer

Gear mesh frequency