SACA Predictive Maintenance and Condition Monitoring

Question 1

What is the key difference between Predictive Maintenance (PdM) and Preventive Maintenance (PM)?

Accepted Answer

PdM uses real-time condition data to service equipment only when degradation is detected; PM services equipment on a fixed time or cycle interval regardless of condition

Answer

PdM is performed after a failure occurs; PM is performed on a fixed schedule

Answer

PM uses sensor data to predict failures; PdM relies entirely on historical MTBF data

Answer

PdM is less expensive to implement than PM because it requires no sensors

Question 2

A maintenance technician uses a vibration analyzer and finds a dominant frequency peak at exactly 1× running speed. This signature most likely indicates:

Accepted Answer

Mass imbalance in the rotating component

Answer

Bearing outer race defect

Answer

Gear mesh frequency problem

Answer

Looseness in the bearing housing

Question 3

Infrared thermography is used in a PdM program primarily to detect:

Accepted Answer

Abnormal heat patterns indicating electrical resistance problems, bearing failures, or refractory degradation

Answer

Shaft misalignment through vibration harmonics

Answer

Lubricant viscosity changes through spectral oil analysis

Answer

Ultrasonic emissions from compressed air leaks

Question 4

What does the P-F curve in predictive maintenance represent?

Accepted Answer

The interval between the point where a potential failure (P) can be detected and the point of functional failure (F)

Answer

The relationship between production output (P) and failure frequency (F) over time

Answer

A plot of preventive (P) vs. failure-based (F) maintenance costs over asset life

Answer

The power factor (P) vs. frequency (F) curve of a motor under varying load

Question 5

Oil analysis as a PdM technique is BEST suited for detecting which type of equipment problem?

Accepted Answer

Internal wear, contamination, and lubricant degradation in gearboxes and hydraulic systems

Answer

Electrical insulation breakdown in motor windings

Answer

Structural resonance in machine frames

Answer

Pipe wall thickness reduction from external corrosion

Question 6

Which metric is used in reliability engineering to quantify the average time between failures for a repairable system?

Accepted Answer

MTBF (Mean Time Between Failures)

Answer

MTTR (Mean Time To Repair)

Answer

OEE (Overall Equipment Effectiveness)

Answer

MTTF (Mean Time To Failure)