Potometer - GCSE Biology Definition

A potometer is a device used to measure the rate of water uptake by a plant, which is used as an estimate of the rate of transpiration. It usually consists of a capillary tube filled with water, into which a freshly cut plant shoot is inserted. As the plant loses water through transpiration, it draws water up through the stem, and the movement of a water bubble in the tube can be measured to calculate how fast water is being taken up. Potometers help GCSE Biology students understand how water moves through a plant and how different factors affect transpiration.