Quick Answer: Ganong Potometer Apparatus is a water-filled potometer for demonstrating transpiration rates and rates of water absorption by a cut shoot under various external conditions, read from an air bubble in a capillary tube of 1 mm bore.
Last updated: October 2026
Key Features
Cut plant shoot sealed into a stopper that fits the end tube
Capillary tube with 1 mm bore; its open end dips into a beaker of water
Glass stopcock admits water from the reservoir to reposition the air bubble
Mounted by spring clips on a varnished wooden base
Base: 20 x 80 mm
Technical Specifications
Specification
Value
Capillary bore
1 mm
Base
Varnished wooden base, 20 x 80 mm
Mounting
Spring clips
Bubble adjustment
Glass stopcock with water reservoir
About This Product
With the shoot sealed in and the whole apparatus filled with water, the air bubble's movement along the capillary shows the rate of uptake, and opening the stopcock lets in water from the reservoir to reset the bubble. Because readings can be repeated under various external conditions, this Biology Lab Equipment item suits comparisons of transpiration and absorption rates.
Frequently Asked Questions
Q1. What is the bore of the capillary tube? The capillary tube of the Ganong Potometer Apparatus has a 1 mm bore.
Q2. How is the air bubble reset in the Ganong Potometer Apparatus? Open the glass stopcock to admit water from the reservoir; this lets the position of the air bubble be adjusted easily.
