TESTING A TRANSPIROMETER

A transpirometer is there for the purpose of measuring plant transpiration. Transpiration can be defined as 'the passage of water through a plant from the roots through the vascular system to the atmosphere'.

The instrument constists of a tube with 3 openings(in one of which the leavy shoots sits). A horizontal thin gradualted cappilary tube is connected to it's horizontal end and leads into a beaker. The beaker controls the constant level of water in the tubes and a reservoir is connected to the system to be able to reset the experiment. The tubes are all filled with water, allowing just one little bubble of air into the capillary tube and sealing the opening to the leavy shoot with a cork and vaseline so that no additional air can come into the system. When the plant transpires, water is supposed to be sucked up by the roots, so that the air bubble will start moving along the graduated caillary tube. The scaling bars on it allow to measure the rate of transpiration.

In my biology class we conducted a set up the transpirometer, the photos of the set up are shown below:

 

http://c1.staticflickr.com/1/458/20406535075_f2432a61b2_n.jpg

http://www.merriam-webster.com/dictionary/transpirometer