检索结果-南通市图书馆

Performance evaluation and calibration of capacitance sensor for estimating the salinity of reclaimed land

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2020年第1期13卷 206-210页

作者： Donggeun Kim Younghwan Son Jaesung Park Taejin Kim Jihun Jeon Department of Rural Systems Engineering Seoul National UniversitySeoul 08826Republic of Korea Department of Rural Systems Engineering and Research Institute for Agriculture and Life SciencesSeoul National UniversitySeoul 08826Republic of Korea Department of Bioresource Engineering McGill UniversitySte-Anne-de-Bellevue QC H9X 3V9Canada

Generally,soil moisture and salinity in reclaimed land are monitored using soil dielectric sensors such as time domain reflectometry,frequency domain reflectometry,and *** soil dielectric sensor measures apparent dielectric ***,apparent dielectric permittivity is affected by soil moisture,salinity,and *** this study,performance evaluation and calibration of a dielectric sensor(5TE;METER Group,Inc.,Pullman,WA,USA)for monitoring soil salinity were *** calibration tests were completed,incorporating various levels of dry density,water content,and *** soil salinity was determined by the electrical conductivity(EC)1:5 *** volumetric water content as measured by the sensor was affected by dry density and water ***,it linearly increased as dry density and water content ***,when dry density or water content was high,the measured value of the sensor increased *** bulk EC measured by sensor had no specific correlation with EC 1:*** EC 1:5 measurement had a linear relationship with the gradient ofθandθ***,it can be estimated with a simple linear equation usingθfrom the soil test andθs from the capacitance *** R 2 value of the EC 1:5 estimation equation was *** proposed equation requiresθfrom the gravimetric sample andθs from the ***,in the case of monitoring salinity using a sensor,it is recommended to measure the water content with a tensiometer.

关键词： salinity capacitance sensor volumetric water content reclaimed land soil saline soil

Study on the MEMS Technique of Flat capacitance sensor with Double Equipotential Rings in Ultra-precise Optical Measurement

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study on the MEMS Technique of Flat Capacitance Sensor with ...

2007亚洲光电子会议量子光学在计算与通信中的应用分会场

作者： Xiao-dong Yang, Jian-huan Zhang Mechanical & electrical engineering dept. of Xiamen university, Xiamen,fujian 361005,China

Geometric measurements based on optical methods have been studied, and the capacitance sensor is applied to detect the focusing displacement. In order to improve the edge effect of the flat capacitance sensor, an equipotential ring is used. According to the Abbe principle, a double equipotential rings flat capacitance sensor with a central hole is developed. The axis of the optical system perforates through the hole of the sensor, thus avoiding the Abbe error. In order to get narrow gap between the equipotential ring and the electrode as well as thin electrodes, MEMS technique is applied to machine the capacitance electrodes, then the gap between the ring and the electrode can be no more than 10μm, meanwhile the measurement accuracy can be promoted greatly. This paper emphasizes on the design of structure flat capacitance sensor and the manufacture of double rings capacitor with MEMS technique. After completing the circuit and finishing the experiment for testing the sensor, it can make further qualitative analysis on the result of the linearity and the sensitivity.

关键词： capacitance sensor Double equipotential rings Microelectromechanical system(MEMS)

The Response of Combined capacitance sensor in The Horizontal Condition

在线全文

cnki会议

学校读者我要写书评

暂无评论

The Response of Combined Capacitance Sensor in The Horizonta...

The 7th International Symposium on Measurement Techniques for Multiphase Flows

作者： Jinhai Hu Xingbin Liu Shuilong Ma Chunhui Huang Lei Li Shuang Yuan Yiwei Li Xiaohua Chen Well Logging Technology Service Company Daqing Oilfield Limited Company

For measurement of the water-cut of the fluid in a low production horizontal well,a combined capacitance sensor is designed which is composed of the cylindrical capacitance sensor and the coaxial capacitance *** two sensors are of parallel connnection in the electric *** of parallel connnection of the two capacitance sensors,the surface area of the combined sensor *** in the non-stratified flow,the oil bubbles are apt to touch the sensor and its measurement resolution is *** in the stratified flow,the cylindrical capacitance which plays a leading role is sensitive to the hight of oil-water *** structure of the sensor is introduced in the *** electric field simulation is conducted and the sensor response in the oil/water stratified flow and bubble flow are *** experiment and dynamic experiment of the sensor are carried out and the response at the different flowrate and water cut is *** results show that the combined capacitance sensor has a higher resolution than the traditional coaxial capacitance *** novel sensor can provide a new technical method to measure the production profile water cut in a low production horizontal well.

关键词： horizontal well capacitance sensor water cut oil-water two phase flow

Finite Element Simulation and Optimization Design of capacitance sensor with Loop Test Plate

在线全文

cnki会议

学校读者我要写书评

暂无评论

Finite Element Simulation and Optimization Design of Capacit...

第26届中国控制与决策会议

作者： Bin Ji Yutao Wang Gang Yang Jinfeng Yuan Northeastern University

Flow pattern is complicated and changeable under the background of dense-phase pneumatic conveying in a horizontal pipe, which has great influence on other flow parameters. If a sensor can detect other parameters of slug combined with the characteristics of the flow pattern, the result will be more accurate. In this paper, in order to solve this problem, a new type of capacitance sensor is put forward, which combines the flow pattern recognition with the concentration detection of slug. The sensor has a high spatial resolution than other sensors. Focusing on the poor sensing field sensitivity uniformity and low measuring sensitivity, an approach combining finite element analysis with orthogonal experiment is proposed to optimally design the sensor. The results of simulation and experiments show that the optimized sensor has a more homogeneous circumferential sensitivity field, and it can detect the slug flow accurately. The sensor is more suitable to test slug than ECT sensor. Therefore, the sensor has a good application prospect in the field of two-phase flow testing.

关键词： capacitance sensor finite-element slug flow pattern recognition

A NEW INSTRUMENT FOR MEASURING LOCAL MOISTURE CONTENTS IN MOIST POROUS MEDIA

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2005年第3期17卷 371-378页

作者： HANJi-tian WANGJi-hao GUIKe-ting SHIMing-heng SchoolofEnergySourceandPowerEngineering ShandongUniversityJinan250061China CollegeofControlScienceandTechnology ShandongUniversityJinan250061China DepartmentofPowerEngineering SoutheastUniversityNanjing210096China

A new instrument was developed for measuring the local moisture content in moist porous media based on the needle-type capacitance sensor and single-chip microprocessor technique. The working principle, the structure and characteristics of the hardware and software of the instrument were presented. The dynamic response characteristics and reliability of the instrument were experimentally determined. As an example, the instrument was employed to measure the heat and mass transport properties of a moist porous material. The experimental results show that the instrument can be used for measuring the local moisture content in moist porous media and would be an effective tool for determining the heat and mass transport properties in moist porous media.

关键词： moisture contents capacitance sensor porous media heat and mass transfer

Capacitive sensor probe to assess frying oil degradation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2015年第2期2卷 142-148页

作者： Alfadhl Yahya Khaled Samsuzana Abd Aziz Fakhrul Zaman Rokhani Department of Biological and Agricultural Engineering Faculty of EngineeringUniversiti Putra MalaysiaSerdangSelangorDarul Ehsan 43400Malaysia Department of Computer and Communication Systems Engineering Faculty of EngineeringUniversiti Putra MalaysiaSerdangSelangorDarul Ehsan 43400Malaysia

The repeated usage of frying oil has been proven hazardous due to the degradation process by chemical reactions that lead to changes in the quality of the ***,the degree of frying oil degradation is indicated by the percentage of its total polar compounds(TPC).In this study,a capacitive sensor was designed to assess frying oil degradation at several heating time intervals by measuring changes on its electrical *** sensor was designed using interdigitated electrode structure.A total of 30 samples of 130 ml palm oil were heated at 180℃ up to 30 *** each one hour interval,one sample was moved out from the laboratory *** electrical capacitance,total polar compound(TPC)and viscosity of the samples were measured for *** results demonstrated significant correlation between oil electrical capacitance with TPC and viscosity with R^2 ranged from 0.83 to *** designed sensor has good potential for simple and inexpensive way of determining frying oil quality.

关键词： capacitance sensor Frying oil quality Heating

Particle size influence on effective permittivity of particle-gas mixture with particle clusters

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2013年第2期11卷 216-224页

作者： Lijun Xu Chang Liu Zhang Cao Xiaomin Li Key Laboratory of Precision Opto-mechatronics Technology Ministry of EducationSchool of Instrument Science and Opto-electronic EngineeringBeihang University School of Chemistry and Environment Beihang University

The influence of particle size on the effective permittivity of a particle-gas mixture in the presence of particle clusters was studied using numerical analysis involving the three-dimensional finite element method. The effective permittivity of the mixture was obtained by calculating the electrostatic energy generated in the computation domain, Numerical results show that for fixed volume fraction of particles in the mixture, the effective permittivity of the mixture increases with decreasing particle size, Static experiments were carried out by using a differential capacitance sensor with parallel plates. The variation of the effective permittivity with particle size is shown by experimental data to agree with the numerical results. The methodology described and the results obtained in this paper may be used to help modify the measurement of particles volume fraction in the presence of particle clusters when a capacitance sensor is used.

关键词： Particle size Effective permittivity Particle clusters Finite element method capacitance sensor

Design of Particle Velocity Measurement System Based on Spatial Filtering Effect of Capacitive sensor

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design of Particle Velocity Measurement System Based on Spat...

第26届中国控制与决策会议

作者： Shen Daoqing Yang Gang Wang Yutao Guo Tingting School of Information Science and Engineering Northeastern University

ISBN: (纸本)9781479937097

When a particle moves through a spatial filter, the output signal contains not only the periodic frequency component related to particle velocity, but also the low frequency component called the pedestal frequency which decreases the signal-to-noise ratio and affects the accuracy of particle velocity measurement. In this paper, a novel spatial filtering method based on capacitive measurement using a differential measurement technology is proposed to remove the pedestal frequency component, in the meanwhile to improve the accuracy and signal-to-noise ratio of the measurement system. Particle velocity measurement system test rig based on spatial filtering effect of capacitive sensor contains AC-based capacitance-voltage transforming circuit, NI DAQ-card, capacitive sensor and computer with LabVIEW2012 programming environment. Experimental data results indicate that the novel spatial filtering method is capable of removing the pedestal frequency component from the output signal with relative error lower than ±2.6% and standard deviation within 0.092 over a velocity range of 2–5 m/s.

关键词： Gas-solid Two-phase Flow capacitance sensor Spatial Filtering Method Particle Velocity Measurement