CMRT CMRT Lubrication and Tribology 2

Question 1

Which contamination type is considered the number one destroyer of lubricated components in industrial machinery?

Accepted Answer

Solid particle contamination

Answer

Solid particle contamination (dirt, wear debris, and dust) is recognized as the primary cause of lubricated component failures because particles accelerate wear and damage surfaces.

Question 2

What does the ISO cleanliness code (e.g., ISO 16/14/11) measure in oil analysis?

Accepted Answer

The number of particles per milliliter at three different size thresholds

Answer

The ISO 4406 cleanliness code reports particle counts per milliliter at three size thresholds (4µm, 6µm, and 14µm), with each number representing a range of particle concentrations.

Question 3

What is the primary advantage of using synthetic lubricants over conventional mineral oils in high-temperature applications?

Accepted Answer

Synthetic oils offer better oxidation stability and wider operating temperature ranges

Answer

Synthetic lubricants provide superior oxidation stability, thermal stability, and maintain useful viscosity across a wider temperature range compared to conventional mineral oils.

Question 4

What is 'over-greasing' a bearing and why is it harmful?

Accepted Answer

Applying excessive grease that causes elevated temperatures, churning, and premature bearing failure

Answer

Over-greasing packs the bearing housing with excess grease, causing the rolling elements to churn the lubricant, generating heat, and ultimately leading to premature bearing failure.

Question 5

Which property of a lubricant is described by its 'flash point'?

Accepted Answer

The lowest temperature at which the oil vaporizes sufficiently to ignite briefly when exposed to a flame

Answer

The flash point is the lowest temperature at which vapors above the oil will briefly ignite when exposed to an open flame, making it an important safety and fire-hazard indicator.

(CMRT) Certified Maintenance and Reliability Technician Practice Test

(CMRT) Certified Maintenance and Reliability Technician Practice Test

CMRT CMRT Lubrication and Tribology 2