Under different light conditions it can measure and analyze the gas evolved by water plants. The gas is circulated into a calibrated capillary tube with the help of one syringe, it is collected into second plastic syringe and taken for further analysis. It consists of a white plastic panel (240 x 100 mm length x height) with miniature 3 way plastic tap, 2 syringes and a calibrated capillary tube approx. 1mm bore. The specimen can be connected to the open end of the tube which is bent downwards.