Stomatal conductance measurements are widely used for energy balance studies, plant stress determination, and drought tolerance analysis. Commercial diffusion porometers have been available for many years but their use was limited byinstrument cost, the need for desiccant, and considerable power requirements for air pumping . A new steady-state porometer is available that has exceptional battery life, does not require any consumables, and is relatively low in cost. The objective of this study was to compare the conductance values measured using the new porometer to existing instruments. Generally, good agreement was found between instruments as long as care was taken to dry desiccant frequently in the older units. Some deviation among units was observed at high conductances, but appeared to be randomly distributed rather than systematic error.