University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Electronics

Classification: Hardware -> Electronics

Citations 4

"Simple Antilog Converter For Conventional And Flow Injection Measurements With Ion-selective Electrodes"
Anal. Chim. Acta 1988 Volume 207, Issue 1-2 Pages 325-330
Marek Trojanowicz and Tadeusz Krawczyski vel Krawczyk, Wodzimierz Augustyniak

Abstract: A simple antilog. converter based on an antilog. amplifier is described. In potentiometric measurements it produced an output voltage which depended rectilinearly on the concentration. of the sensed species over two orders of magnitude. Signals obtained in measurements with Cl-, F-, K+ and Cu(II) ion-selective electrodes ranged from 1.0 to 10.0 V. The converter was used for flow injection potentiometry within one concentration. decade, but its sensitivity depended on the dispersion in the flow system.
Chloride Copper(II) Fluoride Potassium Electrode Electrode Electrode Electrode Potentiometry

"High Performance Optical Absorbance Detectors Based On Low Noise Switched Integrators"
Talanta 1993 Volume 40, Issue 9 Pages 1331-1338
Hanghui Liu, Purnendu K. Dasgupta* and Hong J. Zheng,

Abstract: Circuitry based on switched integrator integrated circuit packages was used to construct optical absorbance detectors with improved peak-to-peak noise levels in liquid phase analysis. The electronics are described and the performance data with light emitting diodes as the light source is given. The noise levels varied from 2-3 µAU at 660 nm to 100 µAU at 605 nm. With a rectangular sample cell (50 µm x 1 mm), a 1 mm path length and a slit width of 50 µm the noise level at 660 nm was 10 µAU and the corresponding limit of detection for bromothymol blue was 10 nM.
Bromothymol blue Spectrophotometry

"Process Monitor For An Ammoniacal Nickel Solution Employing An Infrared Light-emitting Diode And A Log-ratio Amplifier"
Analyst 1995 Volume 120, Issue 10 Pages 2635-2638
Peter C. Hauser, Thusitha W. T. Rupasinghe, Cheryl C. Lucas and Alex McClure

Abstract: An infrared light-emitting diode with peak-emission intensity at 950 nm is used to monitor, online, the concentration of a nickel hexamine carbonate solution; This provides a continuous read-out of the concentration in an extraction stream and is used to control the process at a nickel refinery. Previously the data Was obtained by frequent manual sampling and determination of the concentration by AAS, The transducer employs fiber-optic cables and a beam splitter in Order to allow complete sealing of the opto-electronics and correction for intensity fluctuations of the light source with a log-ratio amplifier, These measures allow the device to function with good performance in a hostile environment of ammonia vapors and large temperature fluctuations. (17 References)
Nickel Process liquor Spectrophotometry

"A Data Acquisition System For Flow Injection Analysis"
Fenxi Shiyanshi 1988 Volume 7, Issue 1 Pages 52-54
Wang Kejun

Abstract: A data acquisition system is described that includes signal collection and amplification, analogue-to-digital conversion and data processing by use of a PC-1500 personal computer. Audible signalling of each stage completion is given. A data acquisition system is described that includes signal collection and amplification, analogue-to-digital conversion and data processing by use of a PC-1500 personal computer. Audible signalling of each stage completion is given.