4�1 Mpd Sensor Cartridge Replacement - Honeywell XNX Technical Manual

XNX Universal Transmitter
Warning: When servicing or replacing sensors, reduce the risk of ignition
of hazardous atmosphere by declassifying the area or disconnecting the
equipment from the supply circuit before opening the sensor enclosure.
Keep the assembly tightly closed during operation.
Warning: Take care when handling sensors as they may contain corrosive
solutions. Do not tamper or in any way disassemble the sensor cell. Do not
expose to temperatures outside the recommended range. Do not expose
the sensor to organic solvents or flammable liquids.
Warning: At the end of their working lives, sensors must be disposed of in an
environmentally safe manner, in accordance with local waste management
requirements and environmental legislation. Sensors should NOT be
incinerated as they may emit toxic fumes.
Warning: Verify all outputs, including display, after installation, after service
events, and periodically to ensure the safety and integrity of the system.
Caution: The following procedure should be followed carefully and
performed only by suitably trained personnel. A fault condition will be
signaled by the sensor if it is removed with the unit under power.
Note: If the power-on self-test was skipped during maintenance activities,
restart the transmitter.
Section 4 - Maintenance
4.1 MPD Sensor Cartridge Replacement
Using Figure 226 as a guide, follow this procedure:
1� Verify that the label on the new sensor is the correct gas
type�
2� Remove power from the transmitter�
3� Unscrew the weatherproof cover (if equipped), loosen the
retainer locking screw, and unscrew the sensor retainer�
4� Remove the old sensor by pulling without twisting�
5� Slide the replacement cell into the MPD body taking care
to align the tab with the alignment slot, then press the cell
firmly to seat it into the body�
6� Refit the sensor retainer, tighten the locking screw and refit
the weatherproof cover (if equipped)�
7� Recalibrate the sensor following the procedures in Section
3�2�2�
Internal O-ring
(critical to performance times)
Figure 226. Removing the Plug-in Sensor
104
Cell Alignment Slot
Sensor Cell
IR or Cat Bead
Sensor Retainer
and Locking Screw