CO2 Sensors

Non-invasive & in-process monitoring

Intro CO2
  • Re-usable & disposable sensors
  • Dissolved carbon dioxide monitoring

The CO2 sensors measure the partial pressure of dissolved carbon dioxide. The spots are fixed on the inner surface of a glassware or transparent plastic material. The CO2 concentration can therefore be measured in a non-invasive and non-destructive manner from outside, through the wall of the vessel.


  • Online monitoring
  • Non-invasive & non-destructive measurement
  • Measurement range from 10 - 250 hPa pCO2 (8 ... 180 mmHg)
  • No consumption of carbon dioxide
  • Measures carbon dioxide in liquids
  • Beta-irradiated and autoclavable sensors available

Selected Probes

Sensor Spots CO2

Sensor Spots CO2

Sensor spots (SP) are the most versatile version of CO2 sensors. They are attached to the inner surface of any transparent vessel.

Examples are

  • Glass bioreactor
  • Sight glass
  • Flasks

The optical fiber of the transmitter can be fixed opposite the SP by using our accessories (see accessories brochure) which can be adapted for nearly all kinds of vessels.

Flow-Through Cell CO2

CO2 Flow-Through Cell FTC-CD1

The flow-through cell carbon dioxide mini-sensor (FTC-CD1) is a miniaturized chemical optical sensor integrated in a flow-through cell. The cell is built from a 3 cm glass tube with 7 mm outer diameter with a CO2 sensor integrated and a customized holder (FTC-Holder) fixing the polymer optical fiber for signal transduction. The cell is autoclavable.

Dipping Probe

Dipping Probe CO2

The CO2 dipping probe is a chemical optical sensor based on 2 mm polymer optical fiber (POF). The sensor membrane is fixed at the tubing end of the optical fiber connected to the transmitter. It is the solution for invasive measurements and monitoring.

Potential Applications

Cell Culture Vessels
Biotechnology: Carbon Dioxide Monitoring in Process Development

In bioprocess development & production, monitoring dissolved CO2 in addition to pH and O2 provides valuable information. It ensures stress-free cultivation conditions during mammalian cell culture (e.g. CHO cell-line). Constant pH and / or oxygen supply and sufficient nutrition levels are key parameters to optimize yield. Thereby, excess CO2 can act as a stressor or even a toxin to the culture and has to be controlled. The chemical optical CO2 sensors can enhance performance of process monitoring during cultivation in disposables, leading to process optimization.

Graph: CO2 Level in CHO Cell Culture
PreSens CO2 Sensors as an Alternative to Off-Line Sampling

PreSens CO2 sensors were evaluated for monitoring the cultivation cells in a 3-L bioreactor. The sensors show excellent long-term stability over a period of 10 days during cell cultivation of CHO cells with an initial seed density of 400,000 cells/mL. The readings of the PreSens CO2 sensor offer the possibility to continuously monitor the CO2 concentration between two off-line measurements.
Rick Baggio, Millipore Corporation, Bedford, MA, USA, Poster Presentation at ESACT2009, Dublin

Blood pCO2 Monitor
Medical Application: Online Monitoring of pCO2

Online monitoring of blood pCO2 is desirable in hypercapnia (pCO2 > 45 mmHg) therapy during point-of-care treatment in intensive care units. During surgeries online monitoring of pCO2 provides continuous fast and reliable information on patients' viability enabling faster clinical decision making compared to standard off-line laboratory analyses based methods. Chemical optical sensors and instrumentation can be integrated (OEM) to monitoring systems, like heart-lung machines, blood parameter control units or blood parameter monitors to provide information for fast clinical decision making.

CO2 Monitoring in Aquaculture of Fish
Scientific: Carbon Dioxide Monitoring for Biological Applications

Increased CO2 uptake from the atmosphere caused by anthropogenic sources is believed to cause ocean acidification, with not yet foreseeable effects on marine life and ecosystem. Monitoring pCO2 in experimental set-ups simulating future levels of carbon dioxide can help to gain knowledge on the effects of ocean acidification on marine fauna. Besides the marine application, monitoring pCO2 also allows knowledge to be gained on land-based plant physiology. Monitoring pCO2 helps increasing yield during aquaculture of fish (fish farming) by providing convenient growth conditions. Excess carbon dioxide levels need to be monitored as this leads to hyperventilation of sea animals.

Working Principle Chemical Optical CO2 Sensors
Dual Lifetime Referencing - An Internal Referencing Method

The chemical optical CO2 sensor is based on our patented DLR measurement principle. The light of the blue LED excites the sensor to emit fluorescence. The luminescence lifetime measured is a superposition of the signals of an analyte sensitive indicator and an inert reference indicator, where both indicators exhibit very different luminescence lifetimes and the luminescence of the analytic sensitive indicator can be suppressed by CO2. The measurement signal correlates to the partial pressure of carbon dioxide.

Technical Data

Please click to enlarge.

Transmitters & Accessories

pCO2 mini Fiber Optic Carbon Dioxide Meter

pCO2 mini

Fiber optic carbon dioxide transmitter



The EOM-CO2-mini is a precise OEM solution for CO2 sensors.

Stick-On Adapter SOA

Stick-On Adapter (SOA)

The Stick-On Adapter (SOA) is used for planar containers.

Coaster CFG

Coaster CFG

The coaster CFG is used for shake flasks.

Adapter for Round Containers ARC

Adapter for Round Containers (ARC)

The ARC is used for round containers with diameters of 2.5 to 20 cm (1 to 8 inches).