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Proceedings Paper

Further development of a self-referenced fiber optic temperature sensor using the contrast characteristics of an LCD segment
Author(s): Julian Mason; Andreas T. Augousti
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Paper Abstract

The authors have previously reported the use of liquid crystals as transducing elements in novel configurations. The use of liquid crystals in these devices relies on the temperature dependence of their alignment and relaxation times when activated in an LCD, as opposed to their more conventional usage when it is their color change with temperature that is utilized. The liquid crystals in these latter instances have been thermotropic, and have not been activated in an electrical fashion. This paper reports the further development of a sensor which uses the temperature dependence of the activation voltage of the liquid crystals in an LCD. The device is self-referenced in that two time-multiplexed signals are produced when the LCD is alternately activated and inactivated. The output signal is a ratio of these two signals and the division is performed using a look-up table. The sensitivity of the system has been increased and additional features added to detect both damage to the probe head/optical fiber and excursion beyond the specific temperature range.

Paper Details

Date Published: 1 November 1994
PDF: 7 pages
Proc. SPIE 2292, Fiber Optic and Laser Sensors XII, (1 November 1994); doi: 10.1117/12.191856
Show Author Affiliations
Julian Mason, Kingston Univ. (United Kingdom)
Andreas T. Augousti, Kingston Univ. (United Kingdom)

Published in SPIE Proceedings Vol. 2292:
Fiber Optic and Laser Sensors XII
Ramon P. DePaula, Editor(s)

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