Decagon's new Leaf Porometer was designed by an agronomist who appreciated the simple porometers he used in his early career. The result is a sleek, innovative, pocket-sized instrument that precisely measures stomatal conductance in less than 30 seconds.

The Leaf Porometer consists of a hand-held enclosure with a cable connected to a leaf-clip sensor. The final reading appears on the display in terms of either conductance or resistance. Saved data can download to a PC using an RS232 cable (included) and download utility software.

The Leaf Porometer measures the stomatal conductance of leaves using the steady state technique. The steady state technique measures the vapor flux from the leaf surface to the atmosphere. A fixed diffusion path is clamped to the surface of the leaf, and the vapor flux is determined from the vapor pressure gradient in the diffusion path and the known vapor conductance through the fixed path. If the vapor flux and the conductance in the diffusion path are known, then the stomatal conductance can be easily calculated.