S104 DOX Differential O2 Analyzer
Moss Photosynthesis Data
S104 DOX Differential O2 Analyzer Moss Photosynthesis Data
S104 DOX Differential O2 Analyzer

Qubit Systems’ S104 Differential O2 Analyzer (DOX) is the world’s only patented differential oxygen analyzer with a resolution of ± 1 ppm O2 against a background of air. With the S104 DOX, researchers can measure real-time rates of respiratory oxygen consumption from tiny insects and photosynthetic oxygen production from a single intact leaf. The S104 Differential O2 Analyzer has the greatest dynamic range of any gas analyzer on the market and on a lower resolution setting it can measure O2 exchange in larger animals, even Human.

When used with a CO2 analyzer (S157) in an open gas exchange system, measurements of Gas Exchange Quotient allow non-invasive studies of respiratory metabolite determination and analyses of reductant flow in anabolic and catabolic reactions.


  • ±1 ppm oxygen resolution against air (that’s 0.0001%!)
  • Widest dynamic range of any oxygen analyzer
  • Easy calibration without special calibration gases
  • Separate analog signals for reference and sample pO2
  • Analog signals for differential pO2, absolute pressure, differential pressure, sample and reference cell temperature, instrument temperature


  • Single Leaf Photosynthetic O2 Exchange
  • Insect Respiratory O2 Consumption
  • Small and Large Animal Respirometry
  • Soil Respiration
  • Leaf Dark Respiration Rate
  • Human Metabolic Studies (Room Calorimetry)


Power Supply 12V 115/220 VAC .
Oxygen Sensor life 3 to 5 years (easily replaceable)
Analog Output 0 to 5 V, Recommend using 16-Bit Analog to Digital converter
Absolute Signal range Reference and Sample  0 to 100% O2
Absolute Signal Resolution 0.001%O2,
Absolute Signal Accuracy  +/- 0.002% O2,
Absolute Signal Response Time T90 = 20 seconds, Partial Pressure measurement.
Differential Oxygen Signal Range 1000 to 10000 ppmO2 (user defined),
Differential Oxygen Signal Resolution 1 ppmO2,
Differential Oxygen Signal Accuracy +/- 2.5 ppmO2,
Differential Oxygen Signal Response Time T90 = 20 seconds, Partial Pressure measurement.
Absolute Pressure Signal Range 15 to 115 kPa,
Absolute Pressure Signal Resolution 0.01 kPa,
Absolute Pressure Signal Noise  < 0.01 kPa,
Absolute Pressure Signal Accuracy 1% of Full Scale.
Differential Pressure Signal Range is +/- 620 Pa,
Differential Pressure Signal Resolution 1 Pa,
Differential Pressure Signal Accuracy 1% of Full Scale.
Reference and Sample Air Temperature Signals Range s 0 to 50 C,
Reference and Sample Air Temperature Signals Resolution 0.01 C,
Reference and Sample Air Temperature Signals Accuracy +/- 0.1 C.
Oven Temperature Signal Range 10 to 50 C,
Oven Temperature Signal Resolution 0.01 C,
Oven Temperature Signal Accuracy +/- 0.1 C.


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