CIRAS-3 Operation Manual V. 1.09  52  support@ppsystems.com 
 
CO
2
/H
2
O Control Columns and H
2
O Equilibrator 
The CO
2
/H
2
O control columns contain 2 clearly marked desiccants labeled CO2 Absorber (soda lime) and 
H2O Absorber (Drierite) which are used to control CO
2
 and H
2
O.  See Desiccants and Absorber Columns 
on page 184 for more information related to this column and management of desiccants.  
TIP 
Always change the Molecular Sieve weekly during use.  See Desiccants and Absorber Columns on page 
184.  We also strongly recommend performing a leak test every time you change the desiccants.  To do 
so insert a fresh CO
2
 cartridge, connect the PLC3 Leaf Cuvette electronically and pneumatically and 
close the cuvette head.  Go to Settings (F2) and set the CO2 reference to 0.  The CO2r and CO2a 
values should drop close to 0 (± 2 ppm) after a few minutes with a 0 CO2d (± 0.5 ppm).