CIRAS-3 Operation Manual V. 1.09  51  support@ppsystems.com 
 
The CO
2
 cartridge manufacturer (iSi) has distributors throughout the world so it should be very easy for all 
customers to source this item locally.  Due to the classification of these CO
2
 cartridges, PP Systems can 
only ship them by ground service in the United States and Canada.  To locate a distributor in your territory 
go to 
https://www.isi.com/ or click on https://www.isi.com/en/culinary/meta/about-isi/contact-isi-sales-partners-
worldwide/ for the latest list of worldwide distributors.  
Manufacturer Contact Information 
ISI 
Kürschnergasse 4 
A-1217 Vienna, Austria 
Tel: +43 1 25099 0   Fax: +43 1 25099 555 
Email: info@isi.at URL: https://www.isi.com/
 
 
NOT ALL CO
2
 CARTRIDGES ARE THE SAME AND SOME MAY EVEN CAUSE DAMAGE IF USED 
WITH THE CIRAS-3.  They come in all different sizes, shapes and contents (some even have oil) and are 
commonly used for things like pellet guns, soda siphons, etc.  If you have any questions whatsoever 
regarding the CO
2
 cartridges you are urged to get in contact directly with PP Systems. 
Gas Ports and Link Pipe 
AIR IN is the entry port for ambient air or introduced air from an external gas cylinder (i.e. experimental air 
containing 2% oxygen).  A short link pipe connects AIR OUT with REF IN.  This is actually the reference 
air supply air for both the reference IRGAs and the leaf cuvette.  For leaf gas exchange measurements 
using any of our PLC3 leaf cuvettes, this link pipe must be connected between the REF IN and AIR OUT.  
The AN OUT and REF OUT ports allow already analyzed air samples to exhaust to atmosphere. 
Auxiliary Connector 
The 4 pin AUX socket is reserved for use with the SRC-1 and SRC-2 Soil Respiration Chambers and the 
CPY-4 and CPY-5 Canopy Assimilation Chambers.   
Please note that the SRC-1 Soil Respiration Chamber and CPY-4 Canopy Assimilation Chamber also 
require another piece of hardware called the Auxiliary Probe Adapter (APA) to work with the CIRAS-3. 
Zero Column 
The Zero column contains 3 clearly marked desiccants labeled CO2 Absorber (soda lime), H2O Absorber 
(Drierite) and MS (Molecular Sieve) which are used for the analyzer Zero ensuring long term stability and 
accuracy of the CO
2
 and H
2
O gas analyzers.  See Desiccants and Absorber Columns on page 184 for 
more information related to this column and management of desiccants.