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6400-09 Soil CO2 Flux Chamber

Making Soil CO2 Flux Measurements with the LI-6400XT

6400-09 Soil CO2 Flux Chamber

The 6400-09 Soil CO2 Flux Chamber is an accessory that provides additional versatility for the LI-6400XT system. The 6400-09 attaches directly to the sensor head of the LI-6400XT — the mixing fan in the sensor head is used to move air through a perforated manifold in the 6400-09, thoroughly mixing the air in the chamber. OPEN instrument software includes a configuration for the 6400-09, simplifying the switch between photosynthesis measurements and soil respiration.

The 6400-09 includes a soil temperature probe that connects to the LI-6400XT, which allows for temperature measurements to be integrated into the data set. Also included with the chamber are PVC soil collars, gaskets, and hardware to interface the 6400-09 with the LI-6400XT sensor head.

The LI-6400XT and the 6400-09 address many of the challenges of making soil CO2 flux measurements, including:

  • The chamber concentration is automatically scrubbed to just below an ambient target, and then measured as it rises to slightly above ambient. This maintains the CO2 concentration gradient to within a few ppm of the natural, undisturbed value.
  • Following each measurement, the intermediate flux data are fit with a regression, which is then used to compute the soil CO2 flux at the target ambient CO2 concentration.
  • Automated cycling ensures that CO2 flux measurements are accurate and repeatable.
  • A pressure equilibration tube is used to eliminate pressure differentials and avoid chamber leaks.
  • Air inside the 6400-09 is thoroughly mixed while maintaining a constant pressure; this, along with a water vapor dilution correction, results in consistently accurate data.

Download the 6400-09 Soil CO2 Flux Chamber Brochure

Download Measurements of Soil CO2 Flux poster

Measuring Soil CO2 Flux?

The LI-8100A Soil CO2 Flux System is ideally suited for this measurement.

LI-8100 Automated Soil CO2 Flux System

LI-8100 Automated
Soil CO2 Flux System

  • Measures CO2 exchange from soils
  • Multiplexed configuration available for larger sampling area
  • Useful for survey or long-term measurements

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