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Proceedings Paper

Colorimetric sensor based on two optical fiber couplers
Author(s): Artur Dybko; Janusz Maciejewski; Ryszard S. Romaniuk; Wojciech Wroblewski
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Paper Abstract

The aim of the paper is to present an idea of a low-cost optical fiber colorimetric pH sensor (with disposable probe). Most of colorimetric sensors consist of two fibers: the illuminating one and one for collecting reflected light. Only one optical fiber is used as a sensing probe in our pH sensor. The end of the fiber is covered by a pH-sensing membrane, which is made of polyvinyl chloride. The colorimetric indicator (bromothymol blue) was immobilized on an ion- exchange resin. The sensing fiber is connected with two optical fiber couplers (type Y). The first coupler guides analytical and reference wavelengths from the light emitting diodes (LED) and the second one transmits light to the photodetector. Only one photodetector is used. Optical signals are filtered electronically because the LEDs are modulated at different frequencies. The results of the measuring tests of the sensor are presented.

Paper Details

Date Published: 15 February 1994
PDF: 6 pages
Proc. SPIE 2085, Biochemical and Medical Sensors, (15 February 1994); doi: 10.1117/12.168753
Show Author Affiliations
Artur Dybko, Warsaw Univ. of Technology (Poland)
Janusz Maciejewski, Warsaw Univ. of Technology (Poland)
Ryszard S. Romaniuk, Warsaw Univ. of Technology (Poland)
Wojciech Wroblewski, Warsaw Univ. of Technology (Poland)

Published in SPIE Proceedings Vol. 2085:
Biochemical and Medical Sensors
Otto S. Wolfbeis, Editor(s)

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