Two-wavelength, multipurpose, truly portable chlorophyll fluorometer and its application in field monitoring of phytoremediation

In this paper a compact, portable instrument is presented for the measureme nt of full chlorophyll fluorescence kinetics of plants at two different wav elengths. The instrument uses a 635 nm laser diode as a light source with v ariable gain driving that allows excitations at selectable actinic levels. The plant fluorescence is detected, at 690 nm and 735 nm, through a special ly mixed three-branch optical fibre bundle. Large scale field monitoring of vegetation is made possible by the utilization of PC/104-form embedded ele ctronics including a low power, IBM PC/386-compatible single board computer (SBC) with non-volatile flash memory. Application of a general purpose SBC and task oriented programming offers in situ data evaluation making proces s control possible. The capabilities of the instrument were demonstrated in monitoring soil phytoremediation processes.