CIRAS-3 Operation Manual V. 1.09
168
It is taking longer than normal for my CO2r levels to settle
•
Under settings your CO2 Reference is likely set to “Fixed analysis air”. Change to “Fixed
reference air”.
I am unable to achieve a Max C calibration above 2000 ppm and it is failing
•
Your CO
2
cartridge is low and needs to be replaced.
•
Your desiccants are exhausted and require replacement. Replace all desiccants.
H
2
O Measurement and Control
My H2Or levels are reading higher than expected
•
There may be a leak somewhere in the gas circuit allowing external ambient air into the system.
Usually this is associated with the absorber columns and the result of a recent desiccant change.
Check that both absorber column assemblies are firmly fitted to the CIRAS-3 console and check
all “O” rings to ensure that they are all firmly seated and not pinched off or cracked.
•
Exhausted H
2
O scrubber in the Zero column. Check the Drierite and replace.
My H2Or levels are reading lower than expected
•
Exhausted H
2
O scrubber in the Zero column. Replace the Drierite and Molecular Sieve.
My H2Or or H2Oa values are fluctuating
•
First I would check your desiccants and change out if exhausted.
•
There may be a leak somewhere in the gas circuit allowing external ambient air into the system.
Usually this is associated with the absorber columns and the result of a recent desiccant change.
Check that both absorber column assemblies are firmly fitted to the CIRAS-3 console and check
all “O” rings to ensure that they are all firmly seated and not pinched off or cracked.
•
Your reference or sampling pump might be dirty or dusty and require cleaning or replacement.
See
Servicing the Air Sampling Pump (Reference & Analysis).
On page 181. Another quick trick
is to simply swap the pumps to see if the problem follows the pump.
•
Dirty air supply unit hydrophobic filter. See
on page 183 for more details.
My H
2
O readings are drifting
•
Exhausted H
2
O scrubber in the Zero column. Replace the Drierite and Molecular Sieve.
