Improved thermal method of continual recording the transpiration flow rate dynamics

The analysis of the dynamic properties of thermal methods of transpiration flow measurement was performed and the measuring system developed, capable of quantitative measurements of fast flow changes (in minutes). The system is specified with a constant automatically maintained temperature difference between the heated and reference points in the measured part of the plant. System’s output signal related to measured quantity is linear. The system has been under longterm testing in full grown trees using the method of heat balance with direct electric heating of the xylem. The results obtained so far may be considered very good.