March 2021
Page 101 of 143
59812-K007 Rev 17
Business Confidential
5.2.3
Contamination Low Fault
As part of the oil mist measurement process light is passed across the sample chamber to illuminate
the oil mist particles in the sampled air. Over time condensing oil can build up on the sample chamber
walls causing the light in the sample chamber to be reduced. The OMD Mk7 Detector constantly monitors
the level of light passing through the sample chamber and produces a fault indication if the light level
drops below a predetermined limit set as part of the detector production process.
If the light level in the sample chamber falls below the allowed limit the detector will communicate the
fault to the Control Unit. The Control Unit will then indicate a contamination low fault, see section 5.1.1.
To identify which detector is at fault, from the Engine Overview Screen, Figure 148, select the required
engine.
Figure 152
Engine Screen Detector Fault
Select the faulty detector to access the Detector Status Screen.
Figure 153
Detector Status Screen LED Fault
Identify the fault being indicated, in this case an LED fault.
Alternatively, an inspection of the engine event log, see section 3.6, will list the event:
Contamination Low Fault
Detector X
Having established which detector is in fault it is necessary to establish the cause of the fault using the
following steps.
1.
Read the parameters of the Mk7 Detector prior to any cleaning taking place. See section 4.5.
This will show the current status of the selected Detector.
2.
See section 4.6 for proper Detector Head removal, cleaning and refitting. Ensure Detector Heads &
Detector base O-Ring seals are properly fitted with Molykote O-Ring Lubricant.
3.
Clean the Detector twice using the recommended cleaning buds and fluid and repeat the Parameter
Reading process.
