CLS CLS Lubricant Storage, Handling & Contamination Control 2 — Questions and Answers
Question 1: Target cleanliness levels for hydraulic systems are typically specified using which international standard?
- ISO 4406 (Correct answer)
- ASTM D445
- NLGI consistency scale
- SAE J306
Correct answer: ISO 4406
ISO 4406 provides the particle count cleanliness code system used to set and verify hydraulic system fluid cleanliness targets.
Question 2: Which filtration rating specification directly describes a filter's ability to remove particles of a specific size under multi-pass test conditions?
- Beta ratio (βx) (Correct answer)
- Absolute micron rating
- Nominal micron rating
- Efficiency percentage at single pass
Correct answer: Beta ratio (βx)
The Beta ratio (βx) from ISO 16889 multi-pass testing quantifies how many particles of size x are upstream versus downstream of the filter.
Question 3: When transferring lubricant from a bulk storage tank to a machine reservoir, which practice most effectively minimizes particle contamination?
- Filtering through a kidney-loop filtration unit rated to system target cleanliness (Correct answer)
- Pouring quickly to limit air exposure
- Using the original container funnel
- Allowing the oil to settle before transferring
Correct answer: Filtering through a kidney-loop filtration unit rated to system target cleanliness
Kidney-loop filtration at the point of transfer removes particles introduced during storage and handling before oil enters the machine.
Question 4: What does the term 'ingression rate' refer to in contamination control?
- The rate at which contaminants enter a lubricated system (Correct answer)
- The rate of oil degradation
- The rate of additive depletion
- The rate of particle removal by filters
Correct answer: The rate at which contaminants enter a lubricated system
Ingression rate quantifies how many particles per unit time enter a system from external sources such as breathers, seals, and fill ports.
Question 5: Which property of a lubricant storage room environment has the greatest impact on moisture contamination of hygroscopic lubricants?
- Relative humidity (Correct answer)
- Ambient light exposure
- Floor material
- Ceiling height
Correct answer: Relative humidity
High relative humidity accelerates moisture absorption into hygroscopic lubricants like polyalkylene glycols (PAGs) and some synthetics.
Question 6: A lubrication technician notices that grease dispensed from a grease gun appears to have separated into oil and thickener. What is the most appropriate action?
- Discard the separated grease and thoroughly clean the gun before reloading (Correct answer)
- Remix the grease and continue use
- Add fresh grease on top and continue use
- Only use the separated oil portion
Correct answer: Discard the separated grease and thoroughly clean the gun before reloading
Oil separation (bleed) indicates degraded grease that will not perform correctly; the gun must be cleaned to avoid contaminating new grease.
CLS CLS Lubricant Storage, Handling & Contamination Control 2
Target cleanliness levels for hydraulic systems are typically specified using which international standard?