Faults 18 - Honeywell MPD Series Operating Manual

5 Faults
The following table provides a list of possible faults related to the sensor together
with possible causes and remedies.
Sensor reads non-zero all the time
Sensor reads non zero when no gas is present
Sensor reads low when gas is applied
Sensor reads high when gas is applied
Sensor reads zero when gas is applied
In the event of exposure to contaminant, e.g. silicones or silicone based products,
or prolonged exposure to high concentration of gas, the sensor should be operated
for 24 hours in a clean environment and then recalibrated.
If the sensor is found to be faulty, or cannot be calibrated, the complete sensor
must be discarded and replaced.
18
Internal O-ring
(critical to performance times)
Cell Alignment Slot
Sensor Retainer
and Locking Screw
Figure 9. Replacing Plug In Sensor
Fault
Sensor Cell
IR or Cat Bead
Cause/Remedy
Gas could be present, ensure there is no
combustible gas in the atmosphere.
Adjust the zero of the control system.
Adjust the span of the control system.
Adjust the span of the control system.
• check the wiring.
• check that the dust protection cap has been
removed.
• check that the sinter is not obstructed.
• replace the sensor if poisoning is suspected.
MPD Operating Manual