Paper
1 August 1990 Device for measuring the microsecond-component of the induction kinetics of the chlorophyll-fluorescence
Bernhard Ruth
Author Affiliations +
Proceedings Volume 1269, Environment and Pollution Measurement Sensors and Systems; (1990) https://doi.org/10.1117/12.20349
Event: The International Congress on Optical Science and Engineering, 1990, The Hague, Netherlands
Abstract
The exciatation light intensity 'e provided by a 6 mW He-Ne laser is switched by a combination of an acousto-optical modulator OS and a mechanical shutter MS. A switching-time below 0.3 s and a power density of 10 mW/cm2 at the object are achieved. Two photoinultipliers measure the fluorescence intensities F685(t) and F730(t) at the two peak wavelengths (685 mu and 730 mn), the nieasuring signals are synchronously stored by a transient recorder with a time resolution of 10 p.s and a capacity of 8000 pairs of measuring values and by a computer with a time resolution which is decreased in steps from 200 1L5 to 200 ins within the total measuring time of 5 mm. The combined use of OS and MS ensures the stability of 'e within 5% during the total measuring time. In addition to the peak intensity F0 and the steady-state intensity F5 which are commonly determined b' devices with low time resolution, the initial intensity Fb and its time derivative Db and intensity F1, time tj, and time derivative D of the inflection point can accurately be determined by the device. The ratio R(t) = F730(t)/F685(t) shows an initial value Rb which is similar to the steady-state-value R5 and two minimum values Rml and Rm2 near 10 ms and 15, respectively.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bernhard Ruth "Device for measuring the microsecond-component of the induction kinetics of the chlorophyll-fluorescence", Proc. SPIE 1269, Environment and Pollution Measurement Sensors and Systems, (1 August 1990); https://doi.org/10.1117/12.20349
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KEYWORDS
Luminescence

Sensors

Head

Pollution

Environmental sensing

Camera shutters

Time metrology

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