How to test the photosynthesis rate

Photosynthesis is the basic substance productive process of all the plants on Earth, especially more than 95% substance of food productive process which we humanity depends are organic substance, which aresynthesized by CO2 and moisture from crop roots, light supplied by the sun and leaf chloroplast. Theprocess that plants synthesize CO2 and moisture to organic substance and release the Oxygen is called Photosynthesis. “How to test the photosynthesis rate” becomes very important for general agriculturalscientists who do the Plant research.

There are many methods to test the photosynthesis rate, but what is most applied method is according the absorption of CO2.

CO2 analyze

Infrared gas analysis, according to the gas molecule made of exotic atom, such as CO2, CO, H2O, SO2, CH3,NH4, NO etc, the gas molecule has specific absorption band within 2.5~25um infrared region. In the middleinfrared  region, there are 4positions for CO2, in 4.26um is the strongest, and do not interfere with H2O.Infrared CO2 gas analysis is to test the CO2 variation when in the process of photosynthesis, by testingabsorption spectrum of CO2 to 4.26um. because of the absorption of 4.6um infrared light of CO2 relates toits absorption factor (K), gas concentration (C) and testing chamber length (L), it follows Bill Lambert Law:Ｅ＝Eoe‐KCL

Because the plant photosynthesis  meter will confirm Eo (the primary energy) and L(chamber length)in the design process,K, e are constant, andＥ(measuring end energy) has a corresponding relationship with C (detected gasconcentration). By testing E, we will get CO2 concentration.

The advantage of Infrared CO2 gas analysis

(1) High sensitivity: be able to measure CO2 concentration of 1.0, 0.5, even 0.1 uml.mlo‐l (ppm).(2)Fast reaction, short response time, it is able to measure instant variation of photosynthesis rate.(3) Easy to measuring, automatically and intelligent.

TOP Cloud -agri plant photosynthesis meter adopts MCU intelligent management technology. Except monitoring CO2 variation, it canalso measure PAR, temperature, and calculate automatically the corresponding photosynthesis (Pn), wateruse efficiency (We) and stomotal conductance (Cleaf).