OMA I
- correct answer
which experience higher unit loads, gear teeth or rolling elements in bearings - correct answer
gear teeth
name three commonly used levels of sample bottle cleanliness - correct answer
clean - fewer that 100 particles greater than 10 micron, superclean - fewer than 10 particles greater that
10 micron, ultraclean - fewer than 1 particle greater than 10 micron per ml of fluid
what kind of engine is particularly susceptible to nitration - correct answer
natural gas engines
what temperature and viscosity units do ISO viscosity grades relate to - correct answer
40°C, centistokes
name a common type of oil that has poor oil/water demulsibility - correct answer
engine oil
what properties of the oil can be tested with spectrochemical analysis - correct answer
wear metals, additives, certain contaminants - all by element
what is the recommended frequency (ASTM D4378) for testing in service turbine oil for viscosity and
TAN - correct answer 500 hours of service
why should air compressor oils not form an emulsion with water - correct answer
to permit efficient separation in the after coolers
what outside examination should be done on all samples of new oils - correct answer
visual (appearance) examination
,what is insoluble in pentane but not in toluene - correct answer insoluble
resinous oxidation products from degraded base oil and some additives
what does TBN mean and what does it measure - correct answer total base
number, alkaline compound (acid neutralizing) left in oil
name six factors that affect the service life of turbine lubricating oils - correct answer
1. Type and design of system, 2. Condition of system at startup, 3. Original oil quality, 4. System
operating conditions, 5. Contamination , 6. Oil make up rate
what does R&O mean - correct answer rust and oxidation inhibited (with
additives)
under what circumstances should deliveries of new lubricating oil be tested - correct answer
the criticality of the equipment warrants the testing, there are questions about oil quality, baseline data
is desired for trending purposes
can flash point measure the degradation of mineral oils - correct answer no, if
a lubricant suffers severe thermal degradation (cracking) the flash point drops
name three ways to test for glycol in engine oils - correct answer
spectrochemical analysis of coolant additives, glycol test, gas chromatography
what does FTIR mean - correct answer Fourier Transform InfraRed
Spectroscopy
what action I soften needed to remove contamination prior to machine startup - correct answer
flushing
how would you express 1% in ppm - correct answer 10,000 ppm
,what is a target cleanliness value - correct answer the maximum allowable
level of solid contaminants
three important reasons to check the viscosity of a used oil are - correct answer
to spot wrong oil, contamination, oil degradation
what does residence time of an oil in a reservoir mean - correct answer the
average time an oil will stay in a reservoir. It is influenced by reservoir size, design and flow rate
what can occur when free water exists in refrigerant lubricants - correct answer
free water droplets can cause freezing and plugging of oilways
what are possible sources of spherical particles - correct answer rolling
element bearing fatigue, fissures, weldspatter, grinding debris
where is the best place to sample wet sump circulating systems - correct answer
after the feed pump, before the filter
what is a goal base limit - correct answer targets set specifically to extend or
maintain oil or machine life
what is an API engine service classification (or categories) - correct answer
designates oil quality levels and is jointly given by API< SAE and ASTM
name two ways water contamination can influence (deplete) additives - correct answer
washes out and hydrolyses certain additives
what does preventive maintenance mean - correct answer maintenance
performed at preset timed intervals
what units are used to represent TAN and TBN values - correct answer mg
KOH/g
, which is a better place to sample a circulation system, the return line header or a well agitated zone of
the reservoir - correct answer return line
what is the difference between a ferrogram and a filtergram - correct answer
ferrogram - glass slide, magnetic and gravimetric deposition, filtergram - porous membrane used to
separate particle by size exclusion
when an oil has thermally degraded, what kinds of problems might be observed - correct answer
sludge, varnish, deposits, viscosity change, additive decomposition
name some possible sources of sulphuric acids in lubricants - correct answer
diesel fuel reaction products, hydrogen sulphide (natural gas compressor), AW and EP additive
breakdown
if two lubricants have been accidentally mixed, how might this be determined using elemental
spectroscopy - correct answer by looking at a change in additive elements
from the baseline
how does fuel dilution influence elemental additive concentrations - correct answer
they decrease
what are vacuum distillation units used for - correct answer to remove free,
emulsified and dissolved water from oil and some other low boiling point contaminants like solvents,
refrigerants, etc
name three common causes for a non-conforming particle count - correct answer
sampling error, instrument error, test procedure error, dirt ingression increase, filter failure, abnormal
wear
the pressure differential across a filter has gone down. What oil properties should be checked - correct
answer viscosity , particle count (collapsed element)
polyalphaolefin, dibasic acid ester, polyol ester, polyglycol, phosphate ester. What class of lubricants are
these - correct answer synthetic fluids
