• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.467-474
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• 2009

In this study, we describe the feasibility of developing a fiber-optic temperature sensor using a thermochromic material such as 2,4,5-triphenylimidazole or also called Lophine. A sensor-tip is fabricated by mixing of a Lophine powder, which has a non-toxic and hydrophobic characteristics, and an epoxy resin. The temperature change in the sensor-tip gives rise to a change in the optical absorbance of the Lophine, and the transmittance of a light through the Lophine is also changed. We have measured the intensities of modulated lights due to the change of optical absorbance of the Lophine by using of a photo-multiplier tube(PMT). The relationships between the temperatures and the output voltages of PMT are determined to measure the temperature of water. The measurable temperature range of the fiber-optic sensor is from 5 to $30^{\circ}C$.

• Journal of Photoscience
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• v.12 no.3
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• pp.137-141
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• 2005

The chemiluminescence reaction of lophine with $H_2O_2$ in alkaline solution has been investigated for use in determination of $Cu^{2+}$ ions. The observed chemiluminescence intensity is found to be a function of the concentration of $Cu^{2+}$. Under the optimum reagent concentrations such as $4{\times}10^{-4}M$ lophine, 0.8 M KOH, 0.2M $H_2O_2,{\lambda}_{em}$, 533nm, the linear range and the detection limit were found to be 0.048ug/ml-48.32ug/ml (R=0.99897) and 0.005ulg/ml respectively. Relative standard deviation for five determinations of 24.16ug/ml $Cu^{2+}$ is 2.35%. The interference from other species was investigated. The proposed method was applied to the determination of $Cu^{2+}$ in different water samples.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1239-1244
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• 2014

In this study, two fiber-optic sensors were fabricated to measure water level and temperature using optical fibers, a coupler, a Lophine and an OTDR (optical time-domain reflectometer). First, using Fresnel's reflection generated at the distal-ends of each optical fiber, which was installed at different depth, we measured the water level according to the variation of water level. Next, we also measured the temperature of water using a temperature sensing probe based on the Lophine, whose absorbance changes with the temperature. The measurable temperature range of the fiber-optic sensor is from $5^{\circ}C$ to $65^{\circ}C$ because the maximum operation temperature of the optical fiber without a physical deterioration is up to $80^{\circ}C$.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.365-366
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• 2009