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In this paper, a cylindrical capacitance sensor with a multi-layer structure was presented. The mathematical model in stratified flow was established and the sensor response in non-stratified flow was also discussed. Results of static experiments agreed well with the stratified model and showed a monotonic relationship between the sensor response and the water holdup. Dynamic experiments were carried...
An electrical resistance tomography sensor consists of a set of measurement electrodes. In general, finite element method (FEM) is used to solve the forward problem (i.e. calculate the resistance value for a given conductivity distribution and electrodes setup). In this paper, a new approach is proposed. The equivalent resistor network model of an electrical resistance tomography (ERT) sensor has...
The need for calibration of large electromagnetic flowmeters(EMF) adds considerably to the cost of these instruments. In order to reduce the cost, this paper discusses a technique for calibration of large electromagnetic flowmeters. The proposed technique based on unit element, moving unit flowrate set to measure the electromotive force of every point in the tube, and adds the weighting function arithmetic...
Steel fiber reinforced concrete structural elements represent very interesting materials which employment has led to tangible advantages in construction technologies over the last decades. The behaviour of this kind of materials is strictly related to the fiber dispersion inside the cementitious matrix. For this reason, in the last years different non destructive measurement methods have been proposed,...
This paper reports recent advances in the optimisation of intrusive electrostatic sensors for the continuous velocity measurement of particles in pneumatic conveying pipelines. The effects of electrode dimensions and intrusion depth on sensor signals and correlation based velocity measurement have been investigated. Different cross sectional shapes of the electrodes have been compared. The optimum...
Interdigital sensors have been successfully employed in various fields; in this paper we attempted to determine the looseness in sheep skins using interdigital sensors. Looseness is one of the quality attributes that determines the value of the leather. A low cost interdigital based sensing system with an effective data acquisition system has been designed.
It is important to measure the water cut of crude oil from oil wells accurately for efficient oil exploitation and production. However, overcoming the effect of salinity in high water cut measurement of oil/water two-phase flow is very difficult. In order to reduce the effect of salinity, a method based on imaginary and real part demodulation is presented in this paper. The impedance of oil/water...
A measurement system is developed for the parameter detection and flow characterization of gas-liquid two-phase flow in micro-channel. Electrical capacitance measurement system and optical measurement system are designed for the micro-channels with different inner diameters of 4.0 mm, 3.1 mm and 1.8 mm respectively. In experiment, bubble flow, stratified flow, slug flow and annular flow are observed...
16-electrode phantoms are developed and studied with a simple instrumentation developed for electrical impedance tomography. An analog instrumentation is developed with a sinusoidal current generator and signal conditioner circuit. Current generator is developed with modified Howland constant current source fed by a voltage controlled oscillator and the signal conditioner circuit consisting of an...
On-line measurement of physical parameters of solution means a great deal in the osmotic dehydration process of food. Ternary solution with NaCl and sucrose is widely employed in this process. This study aims at reconstructing concentrations of two components and estimating density, viscosity of this ternary solution with multifunctional sensing technique in which the multifunctional sensor was previously...
A novel planar interdigital sensor based sensing and instrumentation system has been developed for detection of dangerous contaminated chemicals in seafood. Three novel interdigital sensors have been designed and fabricated. The sensors were designed with different configurations and analyses of all sensors were conducted from the experiments in order to select the best sensor for further analysis...
This paper presents the latest development in the velocity measurement of pulverized coal and biomass fuels in pneumatic pipelines using electrostatic sensors in combination with correlation signal processing techniques. A comparative study of electrostatic sensors with circular and rod electrodes was conducted on a 94mm bore horizontal pipeline feeding a 4 MW industrial scale furnace. Experimental...
A multi-sensor fusion system is applied to the measurement of slug flow in gas/liquid two-phase flow. V-cone meter, correlation technology, cross-section system, and time fusion are adopted in this fusion method. Cross-section sytem is good at the flow regime recognition and cross-section void fraction calculation, while the V-cone meter with its differential pressure model does well in the flow rate...
This paper presents a capacitive measurement principle to detect the formation and accumulation of ice on an overhead power transmission line, for the use with an autonomous monitoring system. The proposed scheme can use either a linear or a circular type electrode geometry. Inter-electrode capacitances are measured by a capacitance-to-digital converter for linear as well as circular type electrodes,...
A new calculable capacitor with an operating range of 0.1 pF is being developed at NIST. Reduced uncertainty for displacement measurements, enabled by employing tunable laser based Fabry-Perot interferometers, will allow a considerably more compact design, minimizing errors from mechanical sources. Using 3-D electric field simulations, we have also estimated errors resulting from mechanical imperfections.
Ground water level measurements are very important for a wide range of applications in geosciences, agriculture, environment monitoring and mining industry. Currently, reliable and automatic ground water level measurements have not been realized. This paper presents the simulation and design of a segmented resistance sensor for measuring ground water level. Based on this sensor design, we have developed...
Capacitance and resistance tomography systems have been developed for visualizing the distributions of materials in an industrial process. They offer certain advantages over other tomography modalities, such as low cost, rapid response, no radiation and being non-intrusive. Single modal tomography could provide a satisfactory solution in most process applications. However, in some more complex applications,...
The paper presents a capacitance-based measurement approach for measuring the flow velocity and the mean density of liquid hydrogen flows. The sensor allows for the measurement of liquid hydrogen flow velocity exploiting a spatial frequency based method for observing gaseous hydrogen bubbles moving through the sensing volume. Additionally, electrodes at both ends of the sensing section are used to...
This study deals with the power electronics packaging and the needs for additional knowledge about electrical pressed contact behavior. For this, a measure bench has been realized. It is able to characterize the pressed interface between a metal electrode and a power chip as a function of the clamping force (0-8000N) and the temperature (up to 100degC). First measurement results show that the electrical...
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