Potometer Ganong's

A Ganong's Potometer on a wooden base is a specialized laboratory apparatus used to measure the rate of transpiration in plants by tracking water uptake. It is a standard tool in school biology labs for demonstrating how environmental factors like light, wind, and humidity affect a plant's water loss. 

• Glassware: Features a graduated, narrow-bore capillary tube (typically 1mm bore) bent at a right angle.
• Reservoir: Includes a vertical funnel or limb with a glass or PTFE stopcock to reset air bubbles and refill the system.
• Shoot Holder: A wide-mouthed glass cylinder or end tube where a freshly cut leafy shoot is sealed using a rubber stopper.
• Base: The entire unit is mounted on a polished, varnished wooden base (approx. 320 x 80mm) with spring clips for stability during experiments. 

1. Setup: The apparatus is filled with water, and a cut plant shoot is sealed into the end tube.
2. Bubble Introduction: A single air bubble is introduced into the graduated capillary tube.
3. Measurement: As the plant transpires, it pulls water from the tube, causing the bubble to move. The distance the bubble travels over a specific time indicates the rate of water uptake.
4. Reset: The stopcock is opened to release water from the reservoir, pushing the bubble back to the starting point for a new trial.