MEASUREMENT OF CO2 AND H2O FLOWS BETWEEN MEDIUM AND PLANTS BY INFRARED GAS ANALYZER BASED ON OPEN GAS EXCHANGE SYSTEM TAKING INTO ACCOUNT INSTRUMENTAL ERROR

Currently, the study of gas exchange in leaves and even entire plants is not difficult. Measurement of gas exchange parameters is, as a rule, carried out using infrared gas analyzers integrated with open gas exchange systems. The measured parameter values are used to evaluate and calculate the physiological processes of interest to the investigator, such as, for example, the rate of absorption of carbon dioxide by the plant during photosynthesis or the rate of release of water vapors during transpiration. In the scientific literature on plant physiology, the error of the result of measuring physiological parameters is given without taking into account the instrumental error, the contribution of which to the total error can be significant, since the physiological parameters of interest to the researcher are mostly indirectly measurable values. This work is devoted to the study of the influence of the error of measuring the parameters of gas exchange of plants obtained using open gas exchange systems on the error of the estimated physiological parameters. The work analyzes equations that are used to estimate the rate of absorption of carbon dioxide and the release of water vapors based on the gas exchange parameters of the plant and are actually standard for open gas exchange systems; issues related to the release of carbon dioxide from the plant in the form of gas during respiratory processes in the light are also considered. An evaluation of instrumental error of carbon dioxide absorption rate measurement during photosynthesis for open gas exchange systems is given.