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May - June 2020
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machinerylubrication.com
TEST YOUR KNOWLEDGE
This month, Machiner y Lubrication continues it s " Test Your Knowledge" sec tion in which we focus on a group of questions from Noria's
Prac tice 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 prac tice test with expanded answers is available at store.noria.com.
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 reser
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voir. 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/move-
ment, and the lubricated part will see foam and air bubbles instead of viscous fluid to
carry the load and prevent metal-to-metal contact.
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 antifoam additive
E) Are the same thing