CIRAS-3 Operation Manual V. 1.09 169 support@ppsystems.com
My H
2
O readings 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.
• Check your H2Or and H2Oa readings. If one of them is fluctuating this will result in a fluctuating
H2Od and you should service the one that is fluctuating. See
Servicing the Air Sampling Pump
(Reference & Analysis). On page 181.
• A leak in the gas circuit usually associated with the leaf cuvette gaskets. See Checking For Leaks
Associated With the PLC3 on page 194 to see if the problem is associated with the PLC3 or
CIRAS-3. Check leaf cuvette gaskets and replace if necessary.
• Cracked or missing “O” ring on the PLC3 pneumatic connector. Replace and periodically
lubricate the “O” rings with silicone grease. See PLC3 Pneumatic Connector on page 196
.
Temperature Measurement and Control
My leaf temperature readings appear to be incorrect
• Are you using the “IR Thermometry” for measurement of leaf temperature? One possibility is that
you are not completely filling the cuvette window with leaf area which will lead to errors in
temperature measurement. In order to use “IR Thermometry” you must fill the chamber with leaf
area. If you are working with small vegetation and you are unable to fill the chamber then you
should select Energy Balance for leaf temperature.
My Tamb value is reading much different than actual ambient
• The Tamb sensor is located at the back of the cuvette handle and is likely in close proximity to
something that is either cooler or warmer than ambient. Try to keep this area of the cuvette away
from any temperature influencing areas.
• Make sure that nothing is covering the small hole at the base of the cuvette handle that contains
the Tamb sensor.
To Next Page
Loading...
Need help?
General
