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

Abstract

In this paper a compact, portable instrument is presented for the measurement of full chlorophyll fluorescence kinetics of plants at two different wavelengths. The instrument uses a 635 nm laser diode as a light source with variable gain driving that allows excitations at selectable actinic levels. The plant fluorescence is detected, at 690 nm and 735 nm, through a specially mixed three-branch optical fibre bundle. Large scale field monitoring of vegetation is made possible by the utilization of PC/104-form embedded electronics 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 process control possible. The capabilities of the instrument were demonstrated in monitoring soil phytoremediation processes.

Excitation kinetics during induction of chlorophyll a fluorescence

“…1), which is based on its predecessor chlorophyll fluorometer (CFM) (Barócsi et al 2000(Barócsi et al , 2003. The main instrument is equipped with a three-branch optical fiber and a sample holder.…”

“…The FMM allows the measuring of the traditional Kautsky induction kinetic curves detected simultaneously at the two maxima of the Chl a fluorescence of leaves (at the 690 nm red and 735 nm far-red bands) as described earlier for the CFM (Barócsi et al 2000). In order to minimize the number of collected data, the hardware timing samples the entire kinetics in quasi-logarithmic time increments (i.e.…”

Characterization And Monitoring Of Natural Attenuation Of Chlorinated Solvents In Ground Water: A Systems Approach

“…Chlorophyll fluorometers are instruments for measuring plant stress and have also been advocated for a variety of evapotranspiration cover and phytoremediation applications (Richter et al 1998;Barocsi et al 2000;Waugh and VanReyper 2003). The BUTE chlorophyll fluorometer, also referred to as CFM-636973 (CFM), measures temporal variation in chlorophyll fluorescence.…”

Special issue in honour of Prof. Reto J. Strasser - Phenotyping with fast fluorescence sensors approximates yield component measurements in pepper (Capsicum annuum L.)

“…Optical techniques present new opportunities to develop novel phenotyping platforms that enable large-scale screenings of genotypes for several traits in multi-location field or greenhouse trials (Montes et al 2007, Furbank andTester 2011). There are several commercial instruments available in the market to determine Chl a fluorescence characteristics (examples are given in Barócsi et al 2000, Strasser et al 2000, Cerovic et al 2012, and Schreiber et al 2012. However, many available fluorescence screening techniques lack the capability of mass-measurement: either the applied method is slow thus the subsequent data evaluation is complicated and/or time consuming, or the recorded signal is only partial, or the apparatus is fixed and cannot be used on agronomic plants in growing conditions.…”