Ganong’s Potometer

Product Code : SCL-LG-11981

The Ganong’s Potometer is a plant-physiology apparatus used for measuring water uptake by a leafy shoot as an indirect estimate of transpiration. It enables students, teachers and laboratory demonstrators to track air-bubble movement through a graduated capillary and compare water absorption under controlled environmental conditions.

Product Description

Ganong’s Potometer uses a graduated, narrow-bore horizontal tube connected to a plant chamber and a water reservoir. The plant shoot draws water through the apparatus, causing an introduced air bubble to move along the capillary scale. Distance travelled over a fixed time provides a comparative water-uptake rate.

The reservoir and stopcock allow the bubble to be returned towards its starting position for repeated observations. Reliable results require an airtight system, stable temperature and a freshly prepared shoot. The capillary bore, graduation interval, glass grade and reservoir volume were not supplied. Compare the apparatus with the listed laboratory potometer.

Key Features

• Graduated capillary tube: Provides a scale for recording air-bubble displacement over time.
• Water reservoir: Maintains the water supply and helps reset the observation bubble.
• Flow-control stopcock: Controls water entry from the reservoir during bubble adjustment.
• Plant chamber: Holds a freshly cut leafy shoot in contact with the water column.
• Comparative measurement: Supports controlled investigations of factors affecting water uptake.
• Repeatable observations: Allows the bubble to be repositioned for additional trials.
• No electrical supply required: Operates through transpiration-related water uptake and capillary displacement.

Technical Specifications

What’s Included in the Kit

• One graduated horizontal capillary tube
• One plant-shoot chamber
• One water reservoir
• One flow-control stopcock
• One funnel or filling section
• Required connecting glass sections

A leafy shoot, rubber stopper, beaker, water, timer, support base and sealing compound are not confirmed as included.

Applications and Uses

• Measuring water uptake by a freshly cut leafy shoot.
• Estimating transpiration indirectly through capillary-bubble movement.
• Comparing water uptake under different light conditions.
• Investigating the effects of temperature, humidity or air movement.
• Calculating bubble displacement per unit of time.
• Teaching the transpiration stream, xylem transport and plant water relations.

Explore complementary teaching apparatus in the biology laboratory equipment category.

How to Use Ganong’s Potometer

1. Inspect the glasswork, capillary, reservoir and stopcock for damage or blockage.
2. Fill the apparatus completely with water and remove unintended air bubbles.
3. Cut a healthy leafy shoot under water to reduce air entry into the xylem.
4. Insert the shoot into the plant chamber and make the connection airtight.
5. Place the open capillary end in a beaker of water.
6. Introduce one observable air bubble into the capillary tube.
7. Use the reservoir and stopcock to position the bubble at a suitable starting mark.
8. Record the distance travelled during a fixed time interval.
9. Reset the bubble and repeat the observation under the same conditions.
10. Change one environmental variable and compare the recorded rates.

Safety note: Wear eye protection and handle the glass apparatus carefully. Use cutting tools only with appropriate supervision. Do not pressurise the system or force tubing and stoppers onto fragile glass connections.

Care & Maintenance

• Rinse the apparatus after use to prevent plant residue from blocking the narrow capillary.
• Operate the stopcock gently and clean it with a method compatible with its material.
• Inspect every seal and connection before use because leakage invalidates observations.
• Store the clean, dry apparatus in a padded or compartmented cabinet.

Why Choose Science Lab Supplies?

Science Lab Supplies manufactures and exports scientific laboratory instruments, educational apparatus and experiment setups. Its range supports schools, colleges, universities and institutional laboratories. Buyers can confirm the capillary scale, glass grade, mounting arrangement and export packing before procurement. Related components can be explored under laboratory glassware.

Frequently Asked Questions

What does Ganong’s Potometer measure?

It measures water uptake by a leafy shoot over time. This is used as an indirect estimate of transpiration.

Why is an air bubble used in the capillary?

The air bubble acts as a visible marker. Its movement indicates water being drawn through the apparatus by the shoot.

What is the purpose of the reservoir?

The reservoir supplies water to the capillary and helps return the bubble towards its starting position for another trial.

Does Ganong’s Potometer measure transpiration directly?

No. It measures water uptake. Some absorbed water may be retained or used by the plant, so the result is an estimate of transpiration.

Why must the setup be airtight?

Air leaks can move the bubble independently of plant water uptake and make the recorded results unreliable.

Can students investigate different environmental factors?

Yes. Students can change one factor, such as light or air movement, while keeping shoot size, time and other conditions consistent.

Confirm the required capillary scale and mounting configuration, then browse more science laboratory equipment from Science Lab Supplies.

Recommended image ALT text: Ganong’s Potometer with graduated capillary, plant chamber, water reservoir and stopcock for measuring plant water uptake.