How it works

The LI-600N brings together numerous innovative technologies to deliver fast, accurate, and dependable measurements in a compact, handheld device.

Stomatal conductance

The LI-600N uses an open flow-through differential measurement for quantifying transpiration (E) and stomatal conductance around the needle or narrow leaf. First, E is quantified by measuring the flow rate and water vapor mole fraction of air that enters and leaves the chamber. Meanwhile, total conductance to water vapor (g_tw) is computed as a function of E and vapor pressure in the leaf and cuvette. Finally, stomatal conductance to water (g_sw) is computed as a function of g_tw and the boundary layer conductance to water vapor (g_bw).

The advantages of the LI-600N measurement flow path include the following:

• FLOW RATES QUICKLY FLUSH THROUGH THE SMALL CHAMBER VOLUME AND RESULT IN RAPID STABILIZATION FOR QUICK MEASUREMENTS
• MINIMALLY DISTURBED LIGHT, CO₂, AND H₂O DURING THE MEASUREMENT ELIMINATE THE NEED FOR DESICCANT CHAMBERS OR CORRECTIONS FOR LARGE DIFFUSION GRADIENTS
• AUTOMATIC MATCHING ACCOUNTS FOR DRIFT BETWEEN THE REFERENCE AND SAMPLE SENSORS

High accuracy at low conductance

Get high-quality, accurate measurements from single needles and blades of grass, even at extremely low conductance.