Equipment and Tools Knowledge Flashcards

A CMMS (Computerized Maintenance Management System) work order history is being used for reliability analysis. Which metric is DIRECTLY calculated from work order timestamps?

Answer: Mean Time To Repair (MTTR)

MTTR is calculated directly from work order start and completion timestamps, representing the average time to restore a failed asset to service.

In a vibration velocity spectrum, a peak at 2× gear mesh frequency with sidebands spaced at shaft speed is MOST likely caused by:

Answer: Gear tooth wear or load distribution problem

Harmonics of gear mesh frequency with shaft speed sidebands indicate gear tooth wear, eccentricity, or uneven load distribution across the gear face.

Which insulation resistance test parameter best indicates the rate of moisture or contamination build-up on motor windings over time?

Answer: Insulation resistance trend over multiple test dates

Trending insulation resistance measurements over time reveals gradual degradation from moisture, contamination, or aging better than any single-point test.

When using a dial indicator to measure shaft runout, a total indicator reading (TIR) of 0.006 inches is recorded. The actual eccentricity of the shaft is:

Answer: 0.003 inches

TIR represents the total diametric variation, so the actual eccentricity (radial offset from true center) is TIR ÷ 2 = 0.003 inches.

A reliability engineer uses a proof test to validate the safety function of a pressure relief valve. The primary purpose of proof testing in this context is to:

Answer: Reveal dangerous undetected failures that accumulate between tests

Proof tests for safety instrumented systems reveal hidden (unrevealed) failures that cannot be detected during normal operation, reducing the probability of failure on demand.

In route-based vibration monitoring, the purpose of using a consistent measurement location marked with a hard-mount stud versus a hand-held probe is to:

Answer: Eliminate variability from probe placement and improve trend repeatability

Consistent mounting locations eliminate probe coupling variability, ensuring that changes in readings reflect actual machine condition rather than measurement technique differences.

When comparing ultrasonic leak detection to soap bubble testing for compressed air system leaks, the primary advantage of ultrasonic detection is:

Answer: Ability to locate leaks while the system is pressurized and operating

Ultrasonic detectors can locate leaks from turbulent gas flow sounds while the system is in full operation, without requiring shutdown or access restriction.