ICML MLA-Machine Lubricant Analyst 1
CERTIFICATION Questions and Correct
Answers
Question 1
Why is seasonal oil viscosity change sometimes practiced in splash-lubricated
gearboxes?
A. To reduce additive usage
B. To match ambient temperature for adequate startup flow and film formation
C. To increase anti-wear additives in summer
D. To change base oil group periodically
Correct Answer
Answer: B
Explanation: Splash systems rely on oil movement; in winter a lower VG helps
startup flow, while in summer higher VG maintains film at operating temperature.
Question 2
A reservoir uses headspace dryers, but water levels keep increasing. Inspection shows
the breather is installed on the return line, not on the tank. What is the likely
problem?
A. Dryer material expired
B. Wrong oil type
C. Dryer is installed in the wrong location, not controlling tank breathing
D. Additive incompatibility
Correct Answer
Answer: C
Explanation: Desiccant breathers must be installed at the reservoir air entry point to
work. Placing them on a return line doesn't address moist air entering during
breathing cycles.
Page 1 of 42
,Question 3
Why is density included when calculating kinematic viscosity from dynamic viscosity?
A. To correct for air entrainment
B. Because ISO VG grades are based on kinematic viscosity (cSt), which is dynamic ÷
density
C. To account for additive depletion
D. To normalize for temperature changes
Correct Answer
Answer: B
Explanation: Kinematic viscosity = dynamic viscosity ÷ density, reported in cSt,
which is the standard for ISO VG classification.
Question 4
Which sampling location typically gives the most representative sample of system
condition for a circulating lube system?
A. Reservoir surface
B. Filter outlet
C. Turbulent zone downstream of the component and upstream of the filter
D. Reservoir drain
Correct Answer
Answer: C
Explanation: This point captures generated contaminants before filters remove them
and is well mixed — ideal for trending.
Page 2 of 42
,Question 5
A trending oil analysis shows a steady increase in Fe (iron) and Cr (chromium), while
Cu (copper) remains flat. The most likely machine source is:
A. Bronze bushing wear (bronze → Cu)
B. Steel/rolling component wear (bearing races, gears, shafts)
C. Seal material wear (elastomeric/graphite)
D. Coolant (glycol) contamination
Correct Answer
Answer: B.
Explanation: Iron and chromium are indicators of ferrous/steel component wear
(bearing steels and gear steels often contain Cr). Copper is indicative of copper-
alloy parts (bushings, brass/bronze). A rising Fe + Cr trend with stable Cu points to
steel/rolling contact wear rather than bronze bushing failure. Always verify with a
wear-metal atlas and trend history.
Question 6
Which of the following is the main reason that splash-lubricated gearboxes often
require seasonal oil viscosity changes in cold climates?
A. Their systems have small reservoirs
B. There is no active temperature control, so oil must be thin enough to flow and
splash at startup
C. Synthetic oils can't handle temperature variation
D. Additives break down at low temperature
Correct Answer
Answer: B
Explanation: Splash systems rely on mechanical agitation to lubricate gears. If the oil
is too viscous in cold conditions, it won't reach components, causing boundary wear
at startup. Seasonal viscosity adjustment or synthetics are common solutions.
Page 3 of 42
, Question 7
Which lubrication regime is most influenced by additive chemistry rather than
viscosity?
A. Hydrodynamic
B. Elasto-hydrodynamic
C. Mixed-film
D. Boundary
Correct Answer
Answer: D
Explanation: In boundary lubrication, there is direct asperity contact, and protection
depends on AW/EP and friction modifier additives, not film thickness.
Question 8
For typical fluid-power hydraulic systems, target cleanliness level (TCL) is closest to
which ISO 4406 code?
A. <18/16/13
B. <17/15/12
C. <16/14/11
D. <15/13/10
Correct Answer
Answer: D.
Explanation: KEW lists target cleanliness levels by application and shows fluid power
/ hydraulic systems generally target <15/13/10 (or better depending on sensitivity).
Use this as a baseline when setting filtration and sampling targets.
Question 9
In a vacuum pump sampling method, why should the sampling tube be placed in the
middle of the oil column, not at the top or bottom?
A. To get warmer oil
B. To avoid surface contaminants (top) and settled debris (bottom), giving a
representative sample
C. To increase flow
D. To mix the oil
Correct Answer
Answer: B
Explanation: Middle-depth sampling avoids surface films and bottom sludge, giving
a more accurate representation of circulating oil condition.
Page 4 of 42
CERTIFICATION Questions and Correct
Answers
Question 1
Why is seasonal oil viscosity change sometimes practiced in splash-lubricated
gearboxes?
A. To reduce additive usage
B. To match ambient temperature for adequate startup flow and film formation
C. To increase anti-wear additives in summer
D. To change base oil group periodically
Correct Answer
Answer: B
Explanation: Splash systems rely on oil movement; in winter a lower VG helps
startup flow, while in summer higher VG maintains film at operating temperature.
Question 2
A reservoir uses headspace dryers, but water levels keep increasing. Inspection shows
the breather is installed on the return line, not on the tank. What is the likely
problem?
A. Dryer material expired
B. Wrong oil type
C. Dryer is installed in the wrong location, not controlling tank breathing
D. Additive incompatibility
Correct Answer
Answer: C
Explanation: Desiccant breathers must be installed at the reservoir air entry point to
work. Placing them on a return line doesn't address moist air entering during
breathing cycles.
Page 1 of 42
,Question 3
Why is density included when calculating kinematic viscosity from dynamic viscosity?
A. To correct for air entrainment
B. Because ISO VG grades are based on kinematic viscosity (cSt), which is dynamic ÷
density
C. To account for additive depletion
D. To normalize for temperature changes
Correct Answer
Answer: B
Explanation: Kinematic viscosity = dynamic viscosity ÷ density, reported in cSt,
which is the standard for ISO VG classification.
Question 4
Which sampling location typically gives the most representative sample of system
condition for a circulating lube system?
A. Reservoir surface
B. Filter outlet
C. Turbulent zone downstream of the component and upstream of the filter
D. Reservoir drain
Correct Answer
Answer: C
Explanation: This point captures generated contaminants before filters remove them
and is well mixed — ideal for trending.
Page 2 of 42
,Question 5
A trending oil analysis shows a steady increase in Fe (iron) and Cr (chromium), while
Cu (copper) remains flat. The most likely machine source is:
A. Bronze bushing wear (bronze → Cu)
B. Steel/rolling component wear (bearing races, gears, shafts)
C. Seal material wear (elastomeric/graphite)
D. Coolant (glycol) contamination
Correct Answer
Answer: B.
Explanation: Iron and chromium are indicators of ferrous/steel component wear
(bearing steels and gear steels often contain Cr). Copper is indicative of copper-
alloy parts (bushings, brass/bronze). A rising Fe + Cr trend with stable Cu points to
steel/rolling contact wear rather than bronze bushing failure. Always verify with a
wear-metal atlas and trend history.
Question 6
Which of the following is the main reason that splash-lubricated gearboxes often
require seasonal oil viscosity changes in cold climates?
A. Their systems have small reservoirs
B. There is no active temperature control, so oil must be thin enough to flow and
splash at startup
C. Synthetic oils can't handle temperature variation
D. Additives break down at low temperature
Correct Answer
Answer: B
Explanation: Splash systems rely on mechanical agitation to lubricate gears. If the oil
is too viscous in cold conditions, it won't reach components, causing boundary wear
at startup. Seasonal viscosity adjustment or synthetics are common solutions.
Page 3 of 42
, Question 7
Which lubrication regime is most influenced by additive chemistry rather than
viscosity?
A. Hydrodynamic
B. Elasto-hydrodynamic
C. Mixed-film
D. Boundary
Correct Answer
Answer: D
Explanation: In boundary lubrication, there is direct asperity contact, and protection
depends on AW/EP and friction modifier additives, not film thickness.
Question 8
For typical fluid-power hydraulic systems, target cleanliness level (TCL) is closest to
which ISO 4406 code?
A. <18/16/13
B. <17/15/12
C. <16/14/11
D. <15/13/10
Correct Answer
Answer: D.
Explanation: KEW lists target cleanliness levels by application and shows fluid power
/ hydraulic systems generally target <15/13/10 (or better depending on sensitivity).
Use this as a baseline when setting filtration and sampling targets.
Question 9
In a vacuum pump sampling method, why should the sampling tube be placed in the
middle of the oil column, not at the top or bottom?
A. To get warmer oil
B. To avoid surface contaminants (top) and settled debris (bottom), giving a
representative sample
C. To increase flow
D. To mix the oil
Correct Answer
Answer: B
Explanation: Middle-depth sampling avoids surface films and bottom sludge, giving
a more accurate representation of circulating oil condition.
Page 4 of 42
