Fiber Bragg Grating Displacement Sensor With High Measurement Accuracy for Crack Monitoring

2019 ◽  
Vol 19 (22) ◽  
pp. 10506-10512 ◽  
Author(s):  
Li Xiong ◽  
Yongxing Guo ◽  
Guozhang Jiang ◽  
Lin Jiang ◽  
Xinglin Zhou
Keyword(s):  
Fiber Bragg Grating ◽  
Measurement Accuracy ◽  
Displacement Sensor ◽  
Bragg Grating ◽  
Crack Monitoring ◽  
High Measurement ◽  
High Measurement Accuracy

Optic Method to Measure the Density of Gas and the Analysis on Uncertainty of Measurement

2011 ◽  
Vol 361-363 ◽  
pp. 226-231
Author(s):  
Chang Li Guo ◽  
Yan Qing Zhang
Keyword(s):  
Refractive Index ◽  
Measurement Accuracy ◽  
Uncertainty Of Measurement ◽  
Interference Theory ◽  
Interference Fringes ◽  
Air Chamber ◽  
High Measurement ◽  
Wedge Structure ◽  
High Measurement Accuracy ◽  
Optical Wedge

A optic method to measure the density of gas is put forward. That is, by using the optical Wedge structure to build air chamber and chamber for gas under test, and by measuring the differences of the optical Wedge interference fringes of the two rooms, the density of gas has been measured. The interference theory of Wedge has been theoretical analyzed, and a formula which can be used to measure the refractive index of gas is put forward, and the uncertainty of the measurement has been analyzed. The parameters of gas density, refractive index and gas thickness have been used in the formula. The results show that the method of optical Wedge interference is practical, and high measurement accuracy is achievement when the density of gas is high.

Developing passive MEMS DC/AC current sensor applicable to two-wire appliances with high measurement accuracy

2016 ◽  
Vol 120 (16) ◽  
pp. 164506 ◽  
Author(s):  
Dong F. Wang ◽  
Xiaodong Li ◽  
Weikang Xian ◽  
Huan Liu ◽  
Xin Liu
Keyword(s):  
Measurement Accuracy ◽  
Current Sensor ◽  
High Measurement ◽  
Ac Current ◽  
High Measurement Accuracy

Metrological Performances of Fiber Bragg Grating Sensors and Comparison with Electrical Strain Gauges

2011 ◽  
Vol 495 ◽  
pp. 53-57
Author(s):  
Marco Borotto ◽  
Enrico De Cais ◽  
Marco Belloli ◽  
Andrea Bernasconi ◽  
Stefano Manzoni
Keyword(s):  
Fiber Bragg Grating ◽  
Thermal Effects ◽  
Measurement Accuracy ◽  
Signal To Noise Ratio ◽  
Bragg Grating ◽  
Light Spectrum ◽  
Static Tests ◽  
Measurement Systems ◽  
Fiber Bragg Grating Sensors ◽  
Fbg Sensors

The fiber Bragg grating sensors (FBGs) have been recently introduced: they present a photorecord grating on the fiber itself, which allows the reflection of a certain wavelength of the input light spectrum. The applied strain is estimated relying on changes of the reflected wavelength. One of the possible applications that has prompted us to study this type of sensors is the possibility to create smart dynamometric structures based on carbon fiber by embedding FBGs. Many papers are available in literature about some applications with smart structures but there is not yet an appropriate metrological characterization about these FBG sensors, their strengths and weaknesses: for these reasons it was deemed useful making several tests on FBG sensors in terms of measurement accuracy, signal to noise ratio, ability to compensate for thermal effects and their behavior for dynamic applications. All these results have been compared to electrical strain gauge ones, which represent the actual reference strain measurement systems. The various solutions to compensate for thermal effects have offered several information for further analyses and the basis for a future use of these sensors for static or semi-static tests. Being fully aware of FBGs characteristics allows to draw down guidelines about their integration in composite materials for the most different applications, understanding in a better way the sensor response.

Research on Velocity Measurement of PD Radar Based on Non-Coherent Accumulation and Waveform Analysis

2014 ◽  
Vol 513-517 ◽  
pp. 2999-3002
Author(s):  
Xu Dong Zhang ◽  
Yun Neng Yuan ◽  
Jun Wang
Keyword(s):  
Radial Velocity ◽  
Target Tracking ◽  
Velocity Measurement ◽  
Measurement Accuracy ◽  
Waveform Analysis ◽  
Radar Target ◽  
Running Time ◽  
Coherent Accumulation ◽  
High Measurement ◽  
High Measurement Accuracy

According to the process of PD radar target tracking, the radial motion of target has a significant impact on velocity measurement. Simulation shows that there is an apparent relation between radial velocity and non-coherent accumulated waveform. Based on the calculation of the entropy of non-coherent accumulated waveform, a method based on waveform entropy in velocity measurement is proposed. Experiments show that the new method can achieve high measurement accuracy, and is insensitive to velocity. At the same time, a rough estimation of velocity is used to shorten the running time.

Evaluation of the metrological characteristics of Raman analyzer of natural gas

2021 ◽  
pp. 67-71
Author(s):  
Dmitry V. Petrov ◽  
Ivan I. Matrosov ◽  
Alexey R. Zaripov ◽  
Aleksandr S. Tanichev ◽  
Matvey A. Kostenko ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Natural Gas ◽  
Measurement Accuracy ◽  
Molar Fraction ◽  
Ecological Systems ◽  
Metrological Characteristics ◽  
Gas Analyzer ◽  
High Measurement ◽  
Academy Of Sciences ◽  
High Measurement Accuracy

The advantages of the Raman spectroscopy method in comparison with gas chromatography in the analysis of the composition of natural gas are described. The metrological characteristics of a Raman gas analyzer developed at the Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences have been studied. A series of measurements were carried out on three natural gas simulators with different concentrations of components. It is shown that Raman gas analyzers are capable of providing high measurement accuracy, close to that of gas chromatographs when analyzing components with a low molar fraction (0.001–0.010 %). It is noted that when analyzing components with a molar fraction in the range of 0.01–100.00 %, the accuracy of the proposed Raman gas analyzer surpassed the accuracy of gas chromatographs.

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