AMI Analyzer Manual
Maintenance and troubleshooting
17
Sensor replacement procedure:
The sensor is provided in a special sealed bag. Do not open this until you are
immediately
about to install the sensor.
Before installing sensor, make sure the power is ON.
1.
Press the ALARM ACKNOWLEDGE.
2.
Turn the gas flow down to zero on the flowmeter.
3.
Unscrew the cell block cap, being careful not to lose the O ring.
4.
Carefully remove old cell by pulling the tab on the label.
5.
Inspect the cell block cavity, and if any sign of moisture clean it out with a Q tip or
similar. Make sure that the contact springs inside the block are intact. Be careful not
to snag them with the Q tip.
6.
Verify that the sealing O ring is in place in the cell cap groove. Verify that the O ring
and the cap are clean and free of any particulate deposits (such as dirt).
7.
Carefully open the bag using a pair of scissors or a knife. Make sure you don’t cut
yourself or stab the sensor! In the rare event that the sensor has leaked there will be
liquid in the bag. If so do not proceed - you need a new sensor. Be careful that you
don’t poke anything such as a fingernail through the membrane.
8.
Don’t pull out the shorting tab yet!
9.
Holding the sensor by its tab, membrane side down, slide it into the cell block (gold
plated contact side of sensor should be facing up touching the cell block contacts.
Make sure the tab is pointing towards the outside so you can pull it out!
10.
When the sensor is pushed in all the way, pull out the shorting tab.
11.
Let the reading stabilize and adjust it after a minute to 20.9%.
12.
Turn up the flow of zero (or sample) gas.
13.
Carefully replace the cap, making sure that you do not cross thread it, and tighten
firmly by hand. Do not over-tighten.
14.
Make sure the zero or sample gas flow is set to 1 SCFH.
15.
Let the reading come down to a low level, and then if desired, calibrate it using a span
gas.
