SENSOR AND PUMP MAINTENANCE
6-5
6.3 Sampling Pump Replacement
The sampling pump is positive displacement piston pump.
When approaching the end of the specified lifetime of the
pump, it will consume a higher amount of energy and reduce its
sample draw capability significantly. When this occurs, it is
necessary to replace the pump.
1. Turn off the IAQRAE, and remove the battery pack.
2. Refer to Figures 6-1 and 6-2. Remove the two hex screws
holding the instrument housing together, then carefully
unscrew four No. 2 screws that hold down the gas piping
plate to the analog PCB and sensors. Remove the gas
piping plate.
3. Carefully loosen the connector. Unscrew the two screws
that hold the pump assembly to the gas plate. Unscrew the
two screws that holding the pump to the PCB. Disconnect
the Tygon tubing that connects the pump to the gas inlet
port.
4. Replace with a new pump assembly. Connect the Tygon
tubing to the gas inlet port. Reattach the pump and screw
down the pump assembly to the analog PCB.
5. Replace the gas piping plate and tighten the four screws to
hold down the sensors.
6. Reattach the hex screws holding the instrument housing
together, and reinstall the battery pack.
