• 한국항만학회지
• /
• 제15권1호
• /
• pp.99-105
• /
• 2001

An on-line refractrometer made of easily obtainable materials is built to determine the salinity and temperature of sea water, and its performance is examined by applying the refractometer to known salt solution. Since refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for accurate measurement. The outcome of salinity measurement for the different concentrations of salt solution indicates that the device is suitable for the salinity measurement by yielding stable and reproducible reading.

• 제어로봇시스템학회논문지
• /
• 제7권5호
• /
• pp.427-431
• /
• 2001

An on-line refractometer made of easily obtainable materials is built to determine the concentration of an alcohol solution, and its performance is examined by applying to the system of ethanol and water. Since the refractive index and the temperature are measured simultaneously, it is possible to compensate the effect of temperature which is not available with an existing on-line refeactometer. Therefore, it can be implemented in the application of process control. The experimental outcome indicates that the home-made refractometer has satisfactory reproducibility and reasonable accuracy for the industrial application.

• 제어로봇시스템학회논문지
• /
• 제9권6호
• /
• pp.473-477
• /
• 2003

An immersion-type on-line refractometer useful for the in-situ measurement of chemical composition and temperature is developed, and its performance is examined by applying the refractometer to known alcohol solution having concentrations between 0 vol. % and 25 vol. %. Because refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of composition measurement for the different concentrations of alcohol solution indicates that the device is suitable for the chemical composition measurement by yielding stable and reproducible reading.

• 센서학회지
• /
• 제14권4호
• /
• pp.286-290
• /
• 2005

We have demonstrated a refractometer for liquid based on a side-polished fiber. The device consists of a side-polished single mode fiber and a rectangular space which plays a role of the multimode planar waveguide when it is infused with a liquid. We presented a simple method to acquire the refractive index of a liquid by use of the spacings of periodic resonance wavelengths of the device. The resolution of the fabricated refractometer was order of $10^{-5}$

• 한국항해항만학회지
• /
• 제26권5호
• /
• pp.571-575
• /
• 2002

해수의 염도와 온도를 현장에서 측정할 수 있는 침적식 온라인 굴절계를 제작하고 실제 해수와 유사한 2 % 내지 4 %의 염수를 사용하여 그 성능을 조사하였다. 굴절률과 온도를 동시에 측정함으로 온도보상을 신속하게 할 수 있어 염도의 직접측정을 가능하게 하였다. 각기 다른 농도의 염용액에서 측정된 염도의 결과로부터 본 실험의 장치는 안정성과 재현성을 모두 갖는 염도 측정이 가능함을 알았다.

• ETRI Journal
• /
• 제36권5호
• /
• pp.841-846
• /
• 2014

This study proposes a novel optical sensor structure based on a refractometer combining a bend waveguide with an air trench. The optical sensor is a $1{\times}2$ splitter structure with a reference channel and a sensing channel. The reference channel has a straight waveguide. The sensing channel consists of a U-bend waveguide connecting four C-bends, and a trench structure to partially expose the core layer. The U-bend waveguide consists of one C-bend with the maximum optical loss and three C-bends with minimum losses. A trench provides a quantitative measurement environment and is aligned with the sidewall of the C-bend having the maximum loss. The intensity of the output power depends on the change in the refractive index of the measured material. The insertion loss of the proposed optical sensor changes from 3.7 dB to 59.1 dB when the refractive index changes from 1.3852 to 1.4452.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2009년도 동계학술발표회 논문집
• /
• pp.507-508
• /
• 2009

We have proposed and demonstrated noncontact refractometer incorporating a fiber bundle. The fiber bundle is composed of a TEC(thermally expended core) fiber and hundreds multimode fibers. The fiber is designed in such a way that the detected reflected optical power from a liquid is constant against the distance between fiber bundle and liquid surface. Low differactive characteristic of TEC fiber make it possible to increase the available distance between the fiber bundle and liquid surface, The obtained sensitivity, optical intensity variation by change of refractive index of liquid is 0.4.

• Journal of the Optical Society of Korea
• /
• 제10권4호
• /
• pp.145-156
• /
• 2006

In the field of ophthalmology, many diagnostic instruments based on optical technology have been developed, such as refractometer, keratometer, corneal mapper, tonometer, fundus camera, slit lamp, laser scan ophthalmoscope and optical coherence tomography. Among them, the refractometer that is used for measuring the refractive power of the human eye has the long research history and various types have been developed. However the efforts to realize more accurate and precise measurement are still in progress. The wavefront analyzer commercialized in recent years is an excellent outcome of such efforts. In this paper, a brief account of the developmental history of various refractometers including the wavefront analyzer is summarized, and the underlying measurement principle is introduced in the view of optics. Finally, the technical issues that should be solved for getting better performance are discussed.

• 동아시아식생활학회지
• /
• 제11권1호
• /
• pp.11-18
• /
• 2001

The saccharification and sensory characteristics of Sikhe, Korean traditional beverage of saccharified rice, made from thirteen glutinous rice varieties and one of non-glutinous rice named I1pum were examined. During saccharification, Shinsunchalbyeo, Whasunchalbyeo, Yukdononhrimna 1 and Hangangchalbyeo showed the highest sweetness determined by refractometer. Yukdononhrimna 1 was good for the morphology and texture of cooked rice kernel during saccharification. There was interrelationship between contents of released reducing sugar and sweetness determined by refractometer during preparation of Sikhe. The overall acceptability determined by sensory evaluation of Sikhe made from Yukdonongrimna 1, was slightly higher than that of Sikhe made from Ilpum, the non-glutionous rice variety. Yukdononhrimna 1 was considered to the most suitable varieties of Sikhe.

• Journal of the Optical Society of Korea
• /
• 제6권3호
• /
• pp.117-120
• /
• 2002

Side-polished single-mode fiber covered with a thick planar-glass-waveguide is studied as a polarization-insensitive fiber-optic refractometer The properties of the device are very sensitive to the index variation of an upper cladding on top of the overlay waveguide. We investigate the spectral response, the polarization properties, and the relationship between the shift in coupling wavelength and the index variation of an upper cladding layer Index resolutions of the order of 10-4 have been achieved.