Eisco B10193A Ganongs Potometer 320mm Long with 1mm Capillary Bore Size

A potometer is an apparatus used to measure the rate of water loss, or transpiration, from a plant. In the Ganong's potometer, the rate of transpiration is determined by measuring the position of an air bubble in a graduated tube over a period of time. The change in position is caused by the plant absorbing water to replace an equal volume of water lost by transpiration.

A plant shoot is sealed into a stopper which fits the end tube and the whole apparatus is filled with water, the open end of the capillary tube, which is graduated in millimetres, dipping into a beaker of water. The position of the air bubble may easily be adjusted by opening the glass stopcock to admit water from the reservoir.

The apparatus is mounted on a wooden base with the tubes held by clips.

* Height to top of reservoir 170mm * Diameter of reservoir 20mm * Length, overall 320mm * Base 80 x 20mm * Capillary bore 1 mm * Eisco type BI0193A