• 제목/요약/키워드: laser measurement

검색결과 2,033건 처리시간 0.038초

The Birefringence measurement of liquid crystal ZLI-1253

  • Cho, Chang-Ho;Jung, Gyoung-Geun;Lee, Tae-Jong;Kim, Chil-Min;Lee, Chul-Se
    • 자연과학논문집
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    • 제1권
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    • pp.7-14
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    • 1987
  • 액정 ZLI-1253 의 복굴절 측정이 파장 및 인가전압 의존도가 He-Ne 레이저와 Ar-ion 레이저를 이용하여 비교 검토된다.

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일일 정도관리를 위한 Daily check device 의 제작 및 효율성 평가 (Daily check device manufacture and efficiency Evaluation for daily Q.A)

  • 김찬용;제영완;이제희;박흥득
    • 대한방사선치료학회:학술대회논문집
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    • 대한방사선치료학회 2005년도 춘계학술대회 초록집
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    • pp.19-22
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    • 2005
  • 방사선 종양학과에서 실시하고 있는 일일 정도관리 항목인 out put laser alignment, field size, SSD indicator 점검을 간편하고 정확하게 할 수 있도록 phantom 모양의 daily check device를 설계하고 제작하였다. 본 장치를 사용하여 4개월(2005. $2\~5$)월 동안 4대의 선형가속기 일일 정도관리에 사용한 곁과 측정과정이 편리하고 시간이 단축되어 일일점검의 효율성이 향상 되었고, 출력선량 측정은 각 장비별로 ${\pm}\;2\%$ 이내였으며 laser, field size, SSD indicator 는 ${\pm}\;1mm$ 이내의 범위에서 측정되었다. 일일 정도관리 기록을 기초로 하여 월간, 연간 정도관리의 객관적인 기초 자료로 활용할 수 있었다. 제작된 daily check device는 기존 상품화된 고가의 측정 장비를 대체 사용가능하게 함으로써 비용절감 효과가 기대되며, 향후 장치 재질의 견고성 및 가벼운 소재의 개발이 필요할 것으로 사료된다.

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Realization of High Precision Position Measurement System Using M-sequence Encoded Laser Beam Scanning

  • Takayama, Jun-ya;Shinji Ohyama;Akira Kobayashi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.107.5-107
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    • 2001
  • In this report, as the active position measurement system, a new method for two-dimensional position measurement system using a concept of semi-open type signal field has proposed. The feature of this system is realizing a position measurement only by scanning the encoded laser beams from scanning points to a measurement field, and observed it. First, both system configuration and encoding method are considered concretely, and M-sequence signal is selected for encoding. Next system design is performed to realize the theoretical measurement accuracy, and applied to a position measurement experiments. Experimental results show that measurement precision is larger than theoretical values. Furthermore, method for improving the measurement ...

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반도체레이져를 이용한 온도 및 농도의 계측 (Temperature and Concentration measurement using Semi-conductor diode laser)

  • 정대헌;노동순;지전유이
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제21회 KOSCO SYMPOSIUM 논문집
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    • pp.168-174
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    • 2000
  • A diode laser sensor system based on absorption spectroscopy techniques has been developed to measure $CO_2$ concentration and temperature non-intrusively in high temperature combustion environments using a 2.0 ${\mu}m$ DFB(Distributed Feedback) laser. Two optics was fabricated in pig-tail fashion and all optical components were implemented in a single box. The evolution of measurement sensitivity was done using test cell by changing sweep frequency and $CO_2$ concentration. Gas temperature was determined from the ratio of integrated line strengths. Species concentration was determined from the integrated line intensity and the measured temperature. The result show that the system has 2% error in wide operation frequency range and accuracy of $CO_2$ concentration was about 3%. The system was applied to measure temperature and concentration in the combustion region of a premixed $CH_4$ +air triangular flame. The measurement results of gas temperature agreed well with thermocouple results. Many considerations were taken into account to reduce optical noise, etalon effect, beam steering and base line matching problem. The evaluations results and actual combustion measurement demonstrate the practical and applicability for in-situ and real time combustion monitoring in a practical system.

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층류화염 유동속도 측정을 위한 modulated LII 기법 (Modulated LII technique for the Measurement of Flow Velocity in Laminar Flames)

  • 이원남;이정수;남연우
    • 한국연소학회지
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    • 제11권3호
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    • pp.36-43
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    • 2006
  • The modulated LII technique has been suggested for the measurement of axial velocity profiles of laminar diffusion flames. The theoretical background is explained based on the blackbody radiation and LII signal. Experimentally, soot particles in ethylene diffusion flames are heated by a modulated Ar-ion laser beam. LII signals and their phase angles are measured using a lock-in amplifier at the different flame heights and the axial flow velocities are obtained from the measured phase angle delay informations. The measured velocities are similar to those from LDV measurements under the same operating conditions. The effects of laser power, LII signal wavelength, and modulation frequencies are not sensitive to the velocity measurement. However, the choice of an optical chopper blade type could affect the measurement result. The use of a 6/5 chopper blade showed the better result that is. possibly due to the square shape of modulated laser beam. This study successfully demonstrated that axial flow velocities of laminar diffusion flames can be measured by a new technique utilizing LII signal, which does not need particle seeding unlikely to LDV or PIV techniques.

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Application of DFB Diode Laser Sensor to Reacting Flow (II) - Liquid-Gas 2-Phase Reacting Flow -

  • Park, Gyung-Min;Masashi Katsuki;Kim, Duck-Jool
    • Journal of Mechanical Science and Technology
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    • 제17권1호
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    • pp.139-145
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    • 2003
  • Diode laser sensor is conducted to measure the gas temperature in the liquid-gas 2-phase counter flow flame. C$\_$10/H/ sub 22/ and city gas were used as liquid fuel and gas fuel, respectively. Two vibrational overtones of H$_2$O were selected and measurements were carried out in the spray flame region stabilized the above gaseous premixed flame. The path-averaged temperature measurement using diode laser absorption method succeeded in the liquid fuel combustion environment regardless of droplets of wide range diameter. The path-averaged temperature measured in the post flame of liquid-gas 2-phase counter flow flame showed qualitative reliable results. The successful demonstration of time series temperature measurement in the liquid-gas 2-phase counter flow flame gave us motivation of trying to establish the effective control system in practical combustion system. These results demonstrated the ability of real-time feedback from combustor inside using the non-intrusive measurement as well as the possibility of application to practical combustion system. Failure case due to influence of spray flame was also discussed.

원통연삭가공시 반도체 레이저 빔을 이용한 금속표면거칠기의 인프로세스 측정 (A Study on the In-process Measurement of Metallic Surface roughness in Cylindrical Grinding by Diode Laser)

  • 김희남
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1995년도 춘계학술대회 논문집
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    • pp.1-8
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    • 1995
  • This paper proposed a simple method for measuring surface roughness of ground surface. utilizing non-contact in-process measuring system using the diode laser. The measurement system is consisted of a laser unit with a diode laser and a cylindrical lens a detecting unit with polygon mirror and CCD array sensor. and a signal processing unit with a computer and device. During operation, this measuring system can provide information on surface roughness in the measuring distance with a single sampling and simultanilusly monitor the state of the grind wheel. The experimental results, showed that the increase of the feed rate and the dressing speed an caused increase in the surface roughness and when the surface roughness is 4Rmax-10Rmax, the cutting speed is 1653m/min-1665m/min. the feed rate is 0.2m/min-0.9m/min, the dressing speed is 0.2mm/rev-0.4mm/rev, the stylus method and the in-process method can be obtained the same results. thus under limited working conditions. using the proposed system. the surface roughness of the ground surface during cylindrical grinding can be obtained through the in-process measurement method using the diode laser.

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