Excursions Into Stomatal Conductance Measurements With the Null Balance Technique.

There are several techniques available for measuring stomatal conductance, ranging from steady state to dynamic to null balance.  Steady state and dynamic porometers are commercially available, but the formerly available null balance porometer has been discontinued.  We have undertaken a project to see if recent advances in electronics, temperature sensing, and air pumping technology lend themselves well to making a miniaturized, low cost null balance porometer with improved performance over historic null balance porometers and possibly over the current steady state and dynamic porometers.  At the time of abstract submission, we have achieved proof-of-concept with a first generation prototype.  With luck, two generations of prototypes will be available for hands-on display, and test results will be presented.