Ametek CEM/Humox, User Manual

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Maintenance and Troubleshooting
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6-13
Process Pressure Checks
To check that you entered the process pressure correctly, select the Process Pressure
menu option from the Setup key. Also ensure that the calibration process pressure
equals normal operating process pressure. Calibration should only be performed
under these conditions for highest accuracy.
Cell Checks
If the cell fails when you first begin to use the analyzer, it is likely that there is a
leak in the sensor plumbing or an improper calibration gas setup, and there is not
a problem with the cell itself (see “Leak Check” in the General Troubleshooting
section for help on how to check for leaks; see the “Calibration” in the Diagnostics
section for help on checking your calibration gas setup).
If the analyzer has been operating for some time, and you feel the oxygen reading
is inaccurate, first check by running a known calibration gas to verify the analyzer’s
response. If the analyzer responds to the calibration gas correctly, it indicates either
leaking or plugged plumbing (see the “Leak Check” and “Plugged Plumbing” checks
later in this chapter).
If your analyzer doesn’t respond properly to the calibration gas, then it may indicate
a problem with the cell. Before replacing the cell, put the analyzer through a primary
calibration and see if this improves the response of the analyzer.
If this doesn’t work, check for leaks or plugged plumbing.
If this doesn’t solve the problem, replace the cell, then run another primary calibra-
tion.