Adam Chromý

This project was realized at Faculty of Electrical Engineering and Communication of Brno University of Technology as my bachelor thesis. Topic of this thesis was assigned by EMS Brno, a small company producing very special environmental mesuring devices.

What is the sap-flow?

Sap-flow is an actual value of current of water with soluted minerals flowing in the trunk of tree of bush. When a plant is photosynthesizing, it "pumps" a water from the ground and it is what we measure.

Principle

This device uses calorimetric measuring principle: when the part of trunk is heated by external source of heat, the temperature difference between heated and non-heated part of the trunk is proportional to the sap-flow. I can be imagined like the flowing water carries away the heat, so we have to have more of heat-power to increase internal temperature by one degree.

My thesis

The aims of my thesis were following:

• Create the mathematical models of system and the device.
• Analyse the cause of unwanted distortion occuring in some cases and design the repairs which would remove these distortions.
• Define the exact conditions of system stability.
• Optimalize the measuring process of device by designing the new controlling algorithm of the heating subsystem.

All of these aims were fulfilled and thesis was evaluated positively. Results of this thesis could be usable in next inovation of this device.

Documents

Here are all public documents about this thesis available for download.

Evaluating of this thesis could be found in Theses Database of Brno University of Technology.