TANDELTA OQSExISG2, User Manual

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wear they will both give a small deviation, however as they progress soot will remain linear and
TBN will become exponential, therefore we are able to differentiate.
The following graphs give examples of different oil degradation patterns allowing you to
identify the specific reasons for oil degradation when compared to the expected degradation.
12.3.1 Oil Degradation
The example graph below shows a steady fall in TDN as the oil deteriorates. Generally, a
steady and consistent change like this is representative of normal time-based oil wear that
occurs within any machinery.
There are some obvious spikes within this data – which is often the case. Here the spikes are
showing ‘improved’ oil condition, which will generally be caused by either erratic temperature
or air. In this example, the spikes coincide with sudden temperature spikes, and so we can
conclude that this is the cause.
The sensors do have temperature corrections which should reduce the amount of condition
change that results from variation in temperature, however there will still be some correlation.
If there is too much noise, then the smoothing function on the sensor can be enabled or
increased. For further guidance on how to adjust the smoothing, please refer to CADS User
Guide for further assistance with Advanced Settings.
Figure 76 - Normal Behaviour
12.3.2 Contamination (Water / Coolant)
The graph below demonstrates what water or coolant contamination can look like in an engine.
The graph begins with a steady trace showing the oil in working condition following an oil
change interval (1). However after a period of time, when the engine is re-started after being
shut down, we see a sudden spike drop in oil condition (2). This then disappears as the water is
thoroughly mixed throughout the oil and then evaporates off. The process is repeated with
varying degrees of severity, while the overall condition of the oil is degrading significantly (3)
which highlights the effect the water is having on the oil.
0
200
400
600
800
1000
O
il
C
o
nd
it
io
n
(T
D
N
)
Total Run Hours
Typical Oil Degradation
Quality (TDN)
Alert Level
Alarm Level
0 9000 3000
6000