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1.
A technique for compensation of temperature effects in fiber grating sensors is reported. For strain sensors and other sensors related to strain such as electromagnetic sensors, a novel structure is designed, which uses two fiber Bragg gratings (FBGs) as strain differential sensor and has temperature effects cancelled. Using this technique, the stress sensitivity has been amplified and gets up to 0.226 nm/N, the total variation in wavelength difference within the range of 3-45 ℃ is 0.03 nm, 1/14 of the uncompensated FBG.The structure can be used in the temperature-insensitive static strain measurement and minor-vibration measurement. 相似文献
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Wook Jae Yoo Jeong Ki Seo Kyoung Won Jang Ji Yeon Heo Jin Soo Moon Jang-Yeon Park Byung Gi Park Bongsoo Lee 《Optical Review》2011,18(1):144-148
In this study, we explored the feasibility of developing two types of fiber-optic temperature sensors that can measure the
temperature of water. One uses a thermochromic material such as Lophine, whose optical absorbance changes according to the
thermal variation. The other uses a thermochromic pigment that gradually loses its own color through heat absorption. We measured
the change in the intensity of the reflected light, which was due to the variation of the optical property of Lophine and
pigments, with thermal variation. The relationship between the temperature of water and the output signal of the fiber-optic
sensors was also determined. The fiber-optic temperature sensor using Lophine provided a relatively broad range of temperature
measurement with low sensitivity, whereas the fiber-optic temperature sensor using a thermochromic pigment offered a high
sensitivity in a narrow range of temperature measurement. 相似文献
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The effect of different scratch techniques, mainly abrasive papers and scalpel blades used to form the junctions of temperature
sensors, on the thermal-product value of these sensors, was examined. A dynamic calibration procedure of scratched sensors
in a shock tube facility which allows easy evaluation of their thermal-product value is outlined. The thermal product of a
particular sensor was found to be dependent on the flow Mach number, junction scratch technique, junction location, and also
on the enthalpy conditions. It was shown that using different scratch techniques normally results in different thermal-product
values of sensors. The experimental procedure used in the present study has yielded practical data on characteristics of scratched
temperature sensors; these data can be used in accurate measurement of transient heat transfer under hypersonic flow conditions. 相似文献
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We have demonstrated a single fiber probe for simultaneous measurement of external refractive index and temperature based on two interferometers: a reflection-mode long-period grating (LPG) for refractometry and an intrinsic Fabry-Perot interferometer (IFPI) for temperature measurement. Since the output signal of the combined structure is a superposition of signals produced by both sensors, which have different spatial frequencies, the original signals needed for the index and temperature measurements can be separated and recovered through digital filters. 相似文献
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基于阵列波导光栅的智能服装人体测温解调系统研究 总被引:1,自引:0,他引:1
研究并实现了一种应用于智能服装中人体温度测量的阵列波导光栅解调系统。分析了系统的解调原理,搭建了光纤布拉格光栅解调实验平台,采用了强度法解调出光纤光栅的布拉格波长,完成了光纤光栅传感器串联前后解调的实验。结果表明,系统对光纤布拉格光栅的布拉格波长的解调具有高线性度,波长测量精度可达0.001 nm,光纤布拉格光栅传感器间串扰所造成的解调误差为0.000 5 nm,人体温度的测量误差为±0.16 ℃。该解调系统精度高、串扰低,可适用于智能服装中人体温度的测量。 相似文献
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Optical Review - Importance of simultaneous measurement of temperature and strain by fiber Bragg grating (FBG) sensors has led to innovation of several renewing techniques. Most of them are based... 相似文献
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应用计算机测定PN结正向压降的温度特性 总被引:3,自引:2,他引:1
采用电热法把待测的PN结放置于温度可连续变化的热源中,利用精确的温度传感器进行温度测量,并利用计算机数据采集技术,直观地再现了PN结正向压降随温度线性变化的整个物理过程,提高了测量的精度. 相似文献
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The interrogation of fiber-Bragg-grating (FBG) sensors using a vertical-cavity surface-emitting laser (VCSEL) is discussed. A long-wavelength (1.54 μm) VCSEL was used as a wavelength-tunable source by variation in the current. Temperature stabilization was performed with a thermoelectric device. Characteristics of temperature and strain sensing were investigated. FBGs with different reflectivities were compared. For temperature sensing, the root-mean-square error in the measurement was reduced to 1/3 that without temperature stabilization. The dependence of the measurement error on the reflectivities of the FBGs was investigated. The measurement error was larger for FBGs with lower reflectivities in both temperature and strain sensing. Improvement on the sensing with low-reflectivity FBGs is discussed. 相似文献
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V. I. Bardyshev 《Acoustical Physics》2002,48(5):518-523
Methods for the simultaneous measurement of the levels of light and heavy liquid phases in a tank by using electroacoustic transducers, temperature sensors, and hydrostatic pressure gauges are considered. According to the calculations, the measurement of the levels of, e.g., oil, petroleum products, and underlying water is possible with relative standard errors of the order of 0.1–1%. 相似文献
13.
Yongbo Dai Yanju Liu Jinsong Leng Gang Deng Anand Asundi 《Optics and Lasers in Engineering》2009,47(10):1028-1033
A novel fiber Bragg grating (FBG) sensor system for measurement of strain and temperature is proposed in this paper. The proposed sensor technique is based on time-division multiplexing (TDM). A semiconductor optical amplifier (SOA), connected in a ring cavity, is used to serve as a gain medium and switch. The SOA is driven by a pulse generator, which operates the SOA at different periods of time to select reflected pulses from a particular sensor. The FBG sensors have identical center wavelengths and can be deployed along the same fiber. This technique relieves the spectral bandwidth issue and permits the interrogation of up to 100 FBGs along a fiber, if the reflectivity of the individual sensors is sufficiently low to avoid shadowing effects. This system is particularly suitable for the application in structural health monitoring (SHM) where large numbers of sensors are required in wide measurement ranges. 相似文献
14.
P. Kisała 《Opto-Electronics Review》2013,21(3):293-302
This paper presents an optoelectronic method for measuring the maximum value of non-uniformly distributed strain at varying temperature. Use of conjugate a gradient algorithm and a sensor model makes it possible to determine the maximum non-uniform strain value and the temperature at which the measurement is performed. The described sensor system enables the maximum strain value to be determined with a linear resolution of 0.003 m. A specially designed measurement system is proposed to verify the plausibility of using uniform fibre Bragg gratings for the simultaneous measurement of two quantities. The possibility of using the spectrum of two grating sensors to determine the maximum value of a non-uniform distribution of strain and temperature values is demonstrated. 相似文献
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基于InGaAs光谱成像技术的光纤光栅传感器在大坝渗流监测系统的应用 总被引:1,自引:0,他引:1
为了实现大坝渗流监测,提出了一种采用光谱成像技术的光纤Bragg光栅传感器和多点传感系统。基于室内实验结果,对监测系统可靠性与监测数据准确度进行和多点传感信号分辨因子分析,结果表明:用于坝体温度场检测的光线光栅传感器波长温度响应灵敏度可达0.009 1nm/℃;由光源带宽决定的测试系统可实现多个传感器的复用。实践表明:采用光纤光栅传感系统可进行大坝渗流自动监测,特别是在系统防雷击、抗干扰性方面,与传统仪器相比具有明显优势。 相似文献
16.
Yu Xu N. Barrie Jones John C. Fothergill Chris D. Hanning 《Optics and Lasers in Engineering》2001,36(6):607-615
An error analysis of two-wavelength absorption-based fibre-optic sensors is presented in this paper. A general formulation to express the measurement error and the error induced by the instability of the light power input into the absorbing sample to be measured is derived. Using this formulation, two common and important errors in this type of sensor, temperature fluctuation of light sources and bending optical fibres, are numerically discussed as illustrative examples. The analyses can be applied to both transmission-type and reflection-type absorption-based fibre-optic sensors. 相似文献
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通常气压传感器的标定补偿方法复杂耗时,开发了一种新的方法去简化气压传感器的标定补偿。首先,设计恒温结构,并通过PID算法自动调节,使气压传感器的核心敏感元件工作于某一个固定温度(此温度稍高于气压传感器需要工作的最高温度点);其次,把气压传感器在与这个固定温度点相等的环境温度下进行标定;最后,完成标定后不管环境温度如何变化,气压传感器敏感元件始终工作在一个恒定的温度,因此气压传感器的标定与补偿可以得到简化。经测试,气压传感器在一定的环境温度范围内实现恒温工作,标定后可以以较高的精度测量气压,实验结果表明经过标定补偿后的气压传感器可以在实际中应用。 相似文献
19.
A temperature sensor based on the thermo-optics effect of single crystal silicon diaphragm was proposed and studied. The temperature measurement mechanism by using single crystal silicon diaphragm was theoretically analyzed and found the relation between temperature measurement range and the thickness of single crystal diaphragm. It was found that when the temperature changed from 20 °C to 48 °C, the reflected resonant peak wavelength was shifted which was detected by using the dual-wavelength signal demodulation method. Experimental results for temperature measurement demonstrated reasonable linearity and repeatability, related linear regression coefficient of the experimental result is 99.94%. The study would be of utility value for the design and fabrication of silicon-based sensors which were used to measure pressure or the other physical quantities. 相似文献
20.
Semiconductor fiber temperature sensors have been used widely in many fields, but most of them pick up temperature by measuring the optical intensity of certain fixed narrow-band in absorption spectrum.Furthermore, they are sensitive to the loss of optical intensity and the fluctuation of light source power.The novel temperature measurement system proposed in this paper is based on the semiconductor absorption theory and the spectral analysis of method. To measure temperature, the sensor model detects not the certain narrow-band spectrum but the most spectra of the optical absorption edge. Therefore the measurement accuracy and the stability can be improved greatly. Experimental results are in agreement with theoretical analysis results perfectly. 相似文献