• 센서학회지
• /
• 제30권1호
• /
• pp.36-41
• /
• 2021

The motivation of this paper is to easily analyze the properties of nondispersive infrared gas sensor that has more than two different optical path length and to suggest the criterion and definition of infrared light absorbance in order to minimize the measurement errors. With the output voltage ratios and the normalized derivatives of infrared ray (IR) absorbance, when the normalized derivatives of IR absorbance decreases from 0.28 to 0.10, the lower and higher limits of errors were decreased from -5.62% and 2.39% to -4.27% and 2.78%. When the normalized derivatives of IR absorbance were 0.10, the output voltage could be partitioned into two regions with one exponential equation and the temperature compensation error was less than 5%.

• 전기전자학회논문지
• /
• 제25권2호
• /
• pp.261-266
• /
• 2021

이 논문에서는 환경 온도 변화를 고려한 열 적외선 데이터 보정 알고리즘을 설계하는 방법을 제시한다. 첫째, 열 적외선 측정 모델은 적외선 측정 데이터와 모델 환경 매개 변수 간의 관계를 사용하여 매개 변수 종속적인 1차 입력-출력 방정식으로 주어지고, 적외선 데이터에 대한 환경 온도의 영향을 보상하기 위해 보상 함수를 구한다. 실험을 통해 제안된 알고리즘이 적외선 데이터에 대한 환경 온도 변화의 영향을 효과적으로 보상할 수 있음을 보인다.

• 센서학회지
• /
• 제26권2호
• /
• pp.141-147
• /
• 2017

A pressure sensor in pulse measurement system is a core component for precisely measuring the pulse waveform of radial artery. A pulse sensor signal that measures the pulse wave in contact with the skin is affected by the temperature difference between the ambient temperature and skin surface. In this study, we found experimentally that the signal changes of the pressure sensors and a temperature sensor were caused by the temperature of the wrist surface while the pressure sensor was contacted on the skin surface for measuring pulse wave. To observe the signal change of the pulse sensor caused by temperature increase on sensor surface, Peltier device that can be kept at a set temperature was used. As the temperature of Peltier device was kept at $35^{\circ}C$ (the maximum wrist temperature), the device was put on the pulse sensor surface. The temperature and pressure signals were obtained simultaneously from a temperature sensor and six pressure sensors embedded in the pulse sensor. As a result of signal analysis, the sensor pressure was decreased during temperature increase of pulse sensor surface. In addition, the signal difference ratio of pressure and temperature sensors with respect to thickness of cover layer in pulse sensor was increased exponentially. Therefore, the signal of pressure sensor was modified by the compensation equation derived by the temperature sensor signal. We suggested that the thickness of cover layer in pulse sensor should be designed considering the skin surface temperature.

• 한국멀티미디어학회논문지
• /
• 제17권11호
• /
• pp.1270-1278
• /
• 2014

The modern infrared (IR) imaging systems use mainly one or more wavelength bands among short wavelength IR (SWIR), middle wavelength IR (MWIR), and long wavelength IR (LWIR) bands. In the process of IR image synthesis and modeling, IR image wavelength-band conversion which transforms arbitrary band image to other band one is required. The wavelength-band conversion procedure includes a temperature estimation process of an object surface. However, in this procedure, an approximated Planck's radiation equation causes errors in estimated temperature. In this paper, we propose an estimation temperature error attenuation method in IR image band conversion procedure. The estimated temperature is corrected with a slope information of radiance according to it. The corrected temperature is used for generation of the other band IR image. The verification of proposed method is demonstrated through the simulation.

• 한국세라믹학회지
• /
• 제22권5호
• /
• pp.54-60
• /
• 1985

This study is concerned with the mechanism of PTCR in $BaTiO_3$ ceramics doped by $Nb^{+5}$ Since the vacancy compensation layer at the grain boundary of n-type doped $BaTiO_3$ ceramics has been known as a major factor for surface state to give PTCR phenomena the dependence of PTCR on such vacancy compensation layer was attemped to be confirmed experimentally in this study. For the experiment quenching and annealing at various temperature after sintering were adopted to induce difference in the thickness of vacancycompensation layer so as to exihibit difference of PTCReffect eachother. The TEX>$Ba^{++}$ cocentration at the grain and grain boundary was measured by EDAX to confirm the formation of the vacancy compensation layer. It was found that i)either decrease in the temperature for quenching ii) or increase in the temperature for annealing improves the PTCR effect clearly iii)increase in TEX>$Ba^{++}$ concentration at the grain boundary results in the improvement of PTCR effect. It was concluded that all the experimental results gave the evidence for the dependence of PTCR effect on the vacancy compensation layer at the grain boundary which had been induced possibly by the $Ba^{++}$ diffusion by the heat treatment conducted.

• 센서학회지
• /
• 제4권1호
• /
• pp.21-28
• /
• 1995

$1000^{\circ}C$까지 비직선 특성을 보상할 수 있는 휴대용 K형 열전대 온도계를 설계 및 제작하였다. 열전대를 이용한 온도계에서 해결해야 할 문제는 비선형특성 보상과 기준점 보상이다. 열전대의 비선형특성은 EPROM을 사용하여 보상하였으며, 기준점 보상은 집적 소자 AD595A를 사용하여 수행하였다. 비선형 특성을 보상하기 전에는 $876^{\circ}C$에서 최대 $23.6^{\circ}C$(2.69%)의 오차가 있었으나, 제작된 휴대용 K형 열전대 온도계로 측정한 결과는 전체 온도 범위 내에서 ${\pm}2^{\circ}C$(0.2%)의 오차 특성을 가진다. 이런 특성은 K형 열전대를 사용하여 측정할 수 있는 상용한도 $1000^{\circ}C$ 범위에서 온도센서의 정밀도 규격을 만족한다. 그러므로 제작된 휴대용 K형 열전대 온도계는 넓은 온도 측정에 비교적 정확하게 사용할 수 있다. 그리고 이러한 비선형 특성을 보상하는 기법은 다른 종류의 온도센서의 보상에 적용할 수 있다.

• 한국정밀공학회지
• /
• 제21권9호
• /
• pp.167-173
• /
• 2004

The heterodyne He-Ne laser interferometer is the most widely used sensing unit to measure the position error. It measures the positioning error from the displacement of a moving reflector in terms of the wave length. But, the wave length is affected by the variation of atmospheric temperature. Temperature variation of 1$^\circ C$ results in the measuring error of 1ppm. In this paper, for measuring more accurately the position error of the ultra precision stage, the refractive index compensation method is introduced. The wave length of the laser interferometer is compensated using the simultaneously measured room temperature variations in the method. In order to investigate the limit of compensation, the stationary test against two fixed reflectors mounted on the zerodur$\circledR$ plate is performed firstly. From the experiment, it is confirmed that the measuring error of the laser interferometer can be improved from 0.34${\mu}m$ to 0.11${\mu}m$ by the application of the method. Secondly, for the verification of the compensating effect, it is applied to estimate the positioning accuracy of an ultra precision aerostatic stage. Two times of the refractive index compensation are performed to acquire the positioning error of the stage from the initially measured data, that is, to the initially measured positioning error and to the measured positioning error profile after the NC compensation. Although the positioning error of an aerostatic stage cannot be clarified perfectly, it is known that by the compensation method, the measuring error by the laser interferometer can be improved to within 0.1${\mu}m$.

• 한국가스학회지
• /
• 제11권1호
• /
• pp.40-45
• /
• 2007

본 논문은 온도보상의 특성을 보여주는 비분산 적외선 이산화탄소 가스센서에 대해 기술하였다. 이 가스센서는 두개의 오목한 반사경을 가진 광 공동, 검출기 출력 전압과 온도센서의 증폭을 위해 동일한 금속 패키지 내에 제작된 ASIC 칩을 포함한 써모파일 검출기로 구성되어 있다. 새롭게 개발된 센서 모듈은 0 ppm에서 2,000ppm까지 이산화탄소 가스의 농도를 측정한 결과 ${\pm}40\;ppm$의 오차를 보였으며, 실험 결과에 기초한 가스농도의 계산 방법으로부터 센서 모듈은 $15^{\circ}C$에서 $35^{\circ}C$ 온도 구간에서 ${\pm}5\;ppm$의 오차를 나타냄으로써 높은 정확성을 가진 자기 온도 보상형 센서를 제작하였다.

• 전력전자학회논문지
• /
• 제3권3호
• /
• pp.165-172
• /
• 1998

USM의 전기 기계적인 변환은 USM의 고정자에 정렬된 PZT트랜듀서를 구동하기 위한 2-상 고주파 전력 변환부와 고정자와 회전자 사이에 마찰력을 변환하는 기계적인 트러로써 나눠지며 이러한 구조특성 때문에 온도에 의한 비선형 특성이 내포하게 된다. 초음파 모터의 외함의 온도가 +2$0^{\circ}C$~3$0^{\circ}C$에서는 정상적인 특성을 나타내지만 장시간의 운전에 의한 모터의 마찰열에 의해 온도증가는 구동주파수, 구동전류, 속도의 감소를 가져온다. 현재 사용되고 있는 초음파 모터는 온도에 대한 보상이 이뤄지지 않고 있다. 본 논문에서는 퍼지제어 기법을 통해 초음파 모터의 운전중 외함의 온도증가에 따른 속도 보상용 시스템을 제안한다.

• Smart Structures and Systems
• /
• 제17권6호
• /
• pp.881-901
• /
• 2016

In this study, a method to compensate the effect of temperature variation on impedance responses which are used for prestress-loss monitoring in prestressed concrete (PSC) girders is presented. Firstly, an impedance-based technique using a mountable lead-zirconate-titanate (PZT) interface is presented for prestress-loss monitoring in the local tendon-anchorage member. Secondly, a cross-correlation-based algorithm to compensate the effect of temperature variation in the impedance signatures is outlined. Thirdly, lab-scale experiments are performed on a PSC girder instrumented with a mountable PZT interface at the tendon-anchorage. A series of temperature variation and prestress-loss events are simulated for the lab-scale PSC girder. Finally, the feasibility of the proposed method is experimentally verified for prestress-loss monitoring in the PSC girder under temperature-varying conditions and prestress-loss events.