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May - June 2014
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www.machinerylubrication.com
ML
This month, Machinery Lubrication continues its "Test Your Knowledge" section in which
we focus on a group of questions from Noria's Practice Exam for Level I Machine
Lubrication Technician and Machine Lubricant Analyst. The answers are located at the
bottom of this page. The complete 126-question practice test with expanded answers
is available at store.noria.com.
1. Which governing body is responsible for
the designation of food-grade lubricants?
A) USDA
B) ISO
C) NSF
D) NLGI
E) ASTM
2. Human sensory (no instrumentation) inspection of machinery can indicate:
A) Excessive water and foaming
B) Excessive heat
C) Highly oxidized, burnt oil
D) Neither A, B or C
E) Answers A, B and C
3. Foam and air entrainment:
A) Are generally not a lubrication problem
B) Can result in oil starvation and/or impair film strength
C) Can result in a change in air pressure in the reservoir
D) Can usually be eliminated by adding more
anti-foam additive
E) Are the same thing
Answers:
1. C
The organization is NSF, which was founded in 1944 as the National Sanitation Foundation. The
name was changed to NSF International in 1990 when the National Sanitation Foundation and
NSF Testing Labs merged.
2. E
For some oils, excessive water content results in an emulsion where the oil looks turbid or milky.
For other oils, it is easy to see free water in the bottom of the reservoir. Foaming can also be easily
seen by inspecting sight glasses. Excessive heat can be sensed by touching surfaces. Oxidized
oil looks dark and has an unpleasant odor. Burnt oil smells like burned food.
3. B
Foam and air entrainment can result in oil starvation due to impaired oil flow/movement, and the
lubricated part will see foam and air bubbles instead of viscous fluid to carry the load and prevent
metal-to-metal contact.
test
your
KNOWLeDGe
