Laser Doppler Vibrometry to detect vessel cavitation

This project was undertaken as a “mini-thesis” under the supervision of Prof. Petrie Meyer as fulfilment of the B.Eng. requirements. This project investigated if a Laser Doppler Vibrometer (LDV) can be used to measure the vibrations of a eucalypt to detect cavitations in the xylem vessels. The cavitations must be detected by and the data recorded by the vibrometer in order to be counted and used to determine the water status of the eucalypt. The results from the study demonstrated the detection of cavitations in the time domain. Distinct peaks could be identified in the measurements taken on Day 2, and when isolating these peaks a decaying response was observed, as expected from the cavitations. Laser Doppler Vibrometry proved to be a viable solution for measuring the vibrations caused by cavitations in young plants with thin bark. This exploratory project was considered a test case to potentially develop further research in this direction.