As a biology teacher for over 30 years I know how difficult it is to measure transpiration rates in plants using a potometer. They are notoriously difficult to set up, and getting reliable class results is a real challenge. I was therefore very pleased to come across this video from the National Science Learning Centre. In the video you will be shown how to set up a demonstration potometer and also one for class use. Just click on the link below:
I hope you find it useful!