Siemens RAPIDLAB 248, Operator'S Manual, Page: 121 / 135

Installing the pH, pCO
2
and pO
2
Sensors
1. Check the level of solution in the pH sensor. It should be full, with a
small air space at the top.
If necessary, empty and refill using pH sensor fill solution. Follow
the instructions on the fill solution pack. Make sure there are no air
bubbles trapped in the bottom of the sensor.
NOTE:
The gas sensors are sealed and cannot be refilled. Tap them
to release any trapped air bubbles before installation.
2. Raise the front cover. Slide the measurement block catch down and
raise the block cover.
3. Insert the sensors in the following order:
p O
2
p CO
2
grounding block pH
NOTE:
The grounding block is in the Spares box.
Slide the sensors into place, making sure that the sensor contacts
align with the contacts in the block.
Installing the Reference Sensor
1. Refer to the reference sensor package insert for filling instructions.
It is particularly important to make sure there are no air bubbles
trapped in the left chamber of the sensor cassette immediately
above the sample pathway. Do not overfill the righthand reservoir
chamber.
2. Swing the block tensioner to the right and insert the reference
sensor from the side. Push the bottom of the sensor to click it into
place. Make sure all the sensors are seated correctly, then push the
tensioner firmly home to make a good seal. Lower the block cover,
snapping it into place.
Connecting the Pump Tubing
1. Tension the sample pump tubes (lefthand pump) by pulling the
tube lugs under the tensioners.
2. Connect the sample tube to the measurement block tube, and the
waste tube to the manifold.
3. Connect the rubber connector to the manifold.
4. Tension the reagent pump tubes (righthand pump) by pulling the
tube lugs under the tensioners.
5. Connect the rubber waste cap connector to the manifold.
6. Make sure there are no kinks in the pump tubing.
7. Date the pump tubing labels a maximum of three months ahead.
Installation Page F-3