Small Diffusive in Situ Soil Gas Probes and Sampling System for Online Soil Gas Measurements

Case ID:

This invention is a small soil gas sampling probe that is connected to an individual recirculating loop that includes a micropump and a multiport selective flow-through valve. This design allows for gas to be recirculated and flow through the recirculating loop until analysis. Analysis of the soil gas sample is performed by small sensors using an online sample equilibration, transfer, and measurement system to determine the concentrations of gas at high spatial and temporal resolution without sampling artifacts.

The composition of gas in soil is a powerful indicator of various important soil processes, including microbial activity, soil carbon stability, agricultural nitrogen efficiency, soil health, presence of beneficial or detrimental biological actors, contamination or bioremediation status, and more. However, most technologies that are currently available to measure are invasive and disruptive to the soil due to their large size, which also causes lower resolution measurements for the gas samples. Current technologies also generally are made of costly materials.

This technology solves issues faced by current soil gas analyzing technologies. It instead is a small probe made from cost-effective material, which is less invasive and disruptive given its small size. Its small size additionally allows for higher spatial resolution measurements. This probe also reflects a more accurate representation of the concentration of gas in soil and is user-friendly due to the automation that is able to measure soil gases online.


  • Measure soil gas concentrations


  • Cost effective
  • Robust -- not easily breakable
  • User friendly
  • Accurate measurements
  • Less invasive and disruptive
  • High spatial and temporal resolution
Patent Information:
Contact For More Information:
Tod McCauley
Assistant Director of Licensing, CALS
The University of Arizona
Lead Inventor(s):
Laura Meredith
Peter Moma
Till Volkmann