Celebrating 40 years.
Quality Instrumentation for the Life Sciences

Effective May 1, 2022, PP Systems will no longer manufacture the CIRAS-3 SC and CIRAS-3 DC. We are evaluating the possibility of a replacement product in the future. We will, however, continue to support both the CIRAS-3 DC and CIRAS-3 SC products. If you have any questions or require additional information please do not hesitate to contact us.

CIRAS-3 SC CO2/H2O Gas Analyzer (Absolute)

The CIRAS-3 SC is a lightweight, robust instrument with a rugged aluminum and polyurethane enclosure making it an ideal instrument for both field and lab.  It features a high performance, absolute CO2 and H2O gas analyzer for measurement of a single gas stream.  Our innovative “Auto Zero” measurement principle ensures long term stability and accuracy of both CO2 and H2O which is a significant advantage over “gas switching” systems.  The gas analyzers include an infrared source, highly polished and gold plated sample cells and specially selected detectors optimized for CO2 and H2O.  The optical bench is temperature-controlled and pressure compensated ensuring the most accurate CO2 and H2O measurements under changing ambient conditions.


  • Plant physiology
  • Soil CO2 efflux
  • Whole canopy assimilation
  • Growth cabinets and environmental control rooms
  • Global change studies
  • CO2 sequestration
  • Forest & agricultural meteorology
  • Air-sea surface exchange (pCO2)
  • Animal/insect respiration
  • Environmental toxicology
  • Volcanology
  • Bioremediation

 Powerful Software

Simple, intuitive and menu-driven software is designed into the system for system setup, operation, recording and data management.  On-line help is available throughout the software to guide you every step of the way.

Numeric Display

Remote Display_Numeric_SC


Graphical Display

Remote Display_Graphic_SC

Gas sampling inlet and outlet ports for direct connection to the gas analyzers

Convenient, pluggable terminal block for analog signals

Product Features

  • High precision instrument featuring 2 independent, non-dispersive infrared gas analyzer for both CO2 and H2O (Absolute Analyzer)
  • CO2 measurement range: Up to 10000 umol mol-1
  • H2O measurement range: 0-75 mb
  • Fast response and long term stability with built-in Auto Zero
  • Fully compensated for changes in temperature, pressure and foreign gas broadening
  • Large, full color 7″ transflective LCD with optimized viewing angle (30o)
  • Large numeric and graphical presentation of data
  • Unlimited data storage (internal memory and USB flash drive)
  • Analog and digital (USB) output
  • Built-in  sampling pump with mass flow controller
  • Powerful, intuitive user interface and software
  • Online Help
  • Remote display capability
  • Internal 7.2V Li-Ion rechargeable battery (optional) for portability
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