A Novel Technique of Flow Measurement for a Conducting Liquid
04 Mar 2009-IEEE Transactions on Instrumentation and Measurement (IEEE)-Vol. 58, Iss: 8, pp 2512-2517
TL;DR: A novel low-cost bridge-type technique of flow measurement of a conducting liquid has been described, and the experimental characteristic of the flowmeter is found to follow the theoretical equation and has good repeatability over the entire operating zone.
Abstract: The flow rate of a conducting liquid is generally measured by an electromagnetic flowmeter, which requires a magnetization coil and a set of sensing electrodes. However, the size and cost of the flow head of this flowmeter generally become very high due to the large size of the magnetizing coil and core material. In this paper, a novel low-cost bridge-type technique of flow measurement of a conducting liquid has been described. In this technique, the lumped-parameter impedances among four electrodes placed at a radial distance apart in a flow-sensing tube form a Wheatstone bridge network. Each of these impedances is a combination of electrode polarization impedances and other impedances. Since the electrode polarization impedances are functions of the flow rate of the conducting liquid and some other parameters, the polarization impedances between two electrodes placed in two locations along the flow path of the conducting liquid may be taken as a measure of the flow rate of the liquid, with the other parameters remaining constant. The nonlinearity of these impedance variations with the flow rate is minimized by the proposed bridge-circuit near-balanced condition. The bridge is excited by a stabilized sinusoidal oscillator and balanced at the no-flow condition of the liquid. The output of the bridge network is converted into a 1- to 5-V dc signal in a signal conditioner circuit. The design aspects, theoretical analysis, and calibration data are presented in this paper. The experimental characteristic of the flowmeter is found to follow the theoretical equation and has good repeatability over the entire operating zone.
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TL;DR: In this paper, an integrated, low-cost, microfluidic-based system for the detection of three such parameters namely, nitrite, pH and electrical conductivity (EC) was presented.
Abstract: Soil harbours innumerable microorganisms, nutrients, and other crucial elements, it anchors vegetation and supplies it with the primary factors that make agriculture possible. Soil health is determined by quantifying nutrients and physical parameters that are required to be in optimum range depending on the cropping pattern. In line with this, the current work presents an integrated, low-cost, microfluidic-based system for the detection of three such parameters namely– nitrite, pH and electrical conductivity (EC). A filtration protocol using different grades of Whatman filter paper was established to detect the said parameters using a suspension of soil. A multiplexed polydimethylsiloxane (PDMS) device was designed and fabricated to test for EC and nitrite. The device employed a conductivity cell with copper electrodes, connected in series with a resistor, powered using an oscillating power source. Griess reaction-based photometric detection using an LED and photodiode was used to quantify nitrite. A transimpedance amplifier circuit was designed and fabricated to amplify the photodiode output. pH detection was achieved using a commercially available pH probe and an Arduino pH breakout board. A low-cost 3D printed syringe pump was developed to achieve flow control. Atmega 328P (onboard Arduino Uno) was used to integrate the subsystems. A smartphone application was built to control the system and store geotagged data. Bluetooth protocol was used to communicate between the smartphone application and Arduino. Standards and real soil samples were tested using the developed microfluidic system.
33 citations
Additional excerpts
...been widely used in microreactor applications [17]–[20]....
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32 citations
TL;DR: Compared with the references existed, the proposed flowmeter in this paper was more compact with good sensitivity, wide measurement range, easy fabrication, and low pressure loss.
Abstract: A small probe-type optical fiber flowmeter was proposed for fluid flow measurement. The hollow cylindrical cantilever was first used to measure the force caused by fluid. A couple of fiber Bragg gratings (FBGs) that were stuck on the inner wall were used to measure the strain of the cantilever. The flow rate can be obtained by monitoring the difference of the two shifted Bragg wavelengths. The cross-sensitivity problem of FBG sensors can be solved by the differential FBG measurement method. Theoretical relation between the Bragg wavelength shift difference and flow rate has been established by theoretical analysis. Meanwhile, experiments have been carried out to verify the feasibility and stability. The simulation and experiment results showed that the resolution of the proposed flowmeter was 0.81 $\text{m}^{3}$ /h and the accuracy was 3.6% in the region of 0–22.5 $\text{m}^{3}$ /h. Compared with the references existed, the proposed flowmeter in this paper was more compact with good sensitivity, wide measurement range, easy fabrication, and low pressure loss.
29 citations
Cites background from "A Novel Technique of Flow Measureme..."
...ACCURATE flow measurement is significant in various applications such as medical, energy, petrochemical engineering, and so on [1], [2]....
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TL;DR: An improved inductance bridge-type technique has been developed to convert the float movement of the rotameter into an electrical current signal, which can be transmitted to a remote indicator.
Abstract: A rotameter is a variable area type flow sensor. It is generally used as a local indicator and display unit. Hence, a special technique is needed to transmit and to display the reading of a rotameter at a remote distance. In this paper, an improved inductance bridge-type technique has been developed to convert the float movement of the rotameter into an electrical current signal, which can be transmitted to a remote indicator. A straight ferromagnetic wire attached to the float of the rotameter acts as a sensing element of the proposed rotameter transducer. The movement of the wire as a result of fluid flow variations inside an inductive pickup coil changes the self-inductance of the coil with the changes in flow rate. An improved inductance bridge network has been used to measure the self-inductance of the coil. It has been observed that the variation of the self-inductance of the pickup coil as well as the variation of the transducer and transmitter outputs with flow rate has a very good linearity and repeatability. The necessary theoretical equations, along with the experimental results, are reported in this paper.
18 citations
Cites methods from "A Novel Technique of Flow Measureme..."
...A novel technique of flow measurement for a conducting liquid has been proposed in [11] where, the lumped parameter polarization impedances among the four electrodes placed at a radial distance apart in a flow tube form a Wheatstone bridge network, which is unbalanced due to flow and its output is taken as a measure of flow rate....
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30 Jun 2017
TL;DR: The main objectives of the present work is to make the intelligent flow measurement technique adaptive to variations in pipe diameter, liquid density& liquid temperature & make a linear relationship between input & output parameter.
Abstract: In this paper an intelligent flow measurement technique is designed by ultrasonic transducers with the help of optimized Fuzzy Logic controller.The main objectives of the present work is to make the intelligent flow measurement technique adaptive to variations in pipe diameter,liquid density& liquid temperature & make a linear relationship between input & output parameter.The output of an ultrasonic flow transducer is frequency which is converted to voltage by using the signal conditioning circuit. For calibration purpose an optimum Fuzzy logic controller is placed instead of conventional calibration circuit and it is test & trained for various values of pipe diameter,liquid density ,liquid temperature & signal conditioning output.The proposed technique is then subjected to the practical data for validation which is done with the help of actual flowrate & output of the intelligent technique.
14 citations
Cites methods from "A Novel Technique of Flow Measureme..."
...For linearization output of ultrasonic flow meter is carried by hardwired analog design in [12,13,16]....
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References
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TL;DR: The recommendations given in the report apply mainly to smooth and homogeneous solid particles and plugs in aqueous systems; some attention is paid to nonaqueous media and less ideal surfaces.
Abstract: In this report, the status quo and recent progress in electrokinetics are reviewed. Practical rules are recommended for performing electrokinetic measurements and interpreting their results in terms of well-defined quantities, the most familiar being the ζ-potential or electrokinetic potential. This potential is a property of charged interfaces and it should be independent of the technique used for its determination. However, often the ζ-potential is not the only property electrokinetically characterizing the electrical state of the interfacial region; the excess conductivity of the stagnant layer is an additional parameter. The requirement to obtain the ζ-potential is that electrokinetic theories be correctly used and applied within their range of validity. Basic theories and their application ranges are discussed. A thorough description of the main electrokinetic methods is given; special attention is paid to their ranges of applicability as well as to the validity of the underlying theoretical models. Electrokinetic consistency tests are proposed in order to assess the validity of the ζ-potentials obtained. The recommendations given in the report apply mainly to smooth and homogeneous solid particles and plugs in aqueous systems; some attention is paid to nonaqueous media and less ideal surfaces.
1,160 citations
Book•
01 Jan 1983
TL;DR: In this paper, the authors present general principles of measurement systems, including reliability, choice and economics of measurement system elements, as well as the accuracy and reliability of the measurement system in the steady state.
Abstract: Part I: General Principles 1. The general measurement system. 2. Static characteristics of measurement system elements. 3. The accuracy of measurement systems in the steady state. 4. Dynamic characteristics of measurement systems. 5. Loading effects and two port networks. 6. Signals and noise in measurement systems. 7. Reliability, choice and economics of measurement systems. Part II: Typical Measurement System elements. 8. Sensing elements. 9. Signal conditioning elements. 10. Signal processing elements. 11. Data presentation elements. Part III: Speciaised Measurement Systems 12. Flow measurement systems. 13. Intrinsically safe measurement systems. 14. Heat transfer effects in measurement systems. 15. Optical measurement systems. 16. Ultrasonic measurement systems. 17. Gas chromatography. 18. Data acquisition. Answers to numerical problems. Index.
347 citations
"A Novel Technique of Flow Measureme..." refers methods in this paper
...THE MEASUREMENT of the volume flow rate of a conducting liquid is generally done in process industries by using electromagnetic flowmeters [4]–[6], [12], since this technique is very simple compared with the other methods....
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TL;DR: The validity of the model is demonstrated with human leukemia (HL-60) cells subjected to a parallel electrode array, and application of the device to separating HL-60 cells from peripheral blood mononuclear cells is shown.
Abstract: We present the principle of cell characterization and separation by dielectrophoretic field-flow fractionation and show preliminary experimental results. The operational device takes the form of a thin chamber in which the bottom wall supports an array of microelectrodes. By applying appropriate AC voltage signals to these electrodes, dielectrophoretic forces are generated to levitate cells suspended in the chamber and to affect their equilibrium heights. A laminar flow profile is established in the chamber so that fluid flows faster with increasing distance from the chamber walls. A cell carried in the flow stream will attain an equilibrium height, and a corresponding velocity, based on the balance of dielectrophoretic, gravitational, and hydrodynamic lift forces it experiences. We describe a theoretical model for this system and show that the cell velocity is a function of the mean fluid velocity, the voltage and frequency of the signals applied to the electrodes, and, most significantly, the cell dielectric properties. The validity of the model is demonstrated with human leukemia (HL-60) cells subjected to a parallel electrode array, and application of the device to separating HL-60 cells from peripheral blood mononuclear cells is shown.
314 citations
TL;DR: The polarisation impedance of the platinum electrode was measured in physiological saline over six decades of frequencies down to 1 mHz and demonstrated the validity of Schwan’s limit law of linearity at very low frequencies.
Abstract: The polarisation impedance of the platinum electrode was measured in physiological saline (0·9% NaCl) over six decades of frequencies down to 1 mHz. The applicability, of Fricke’s phase angle rule was verified down to 10 mHz. The resistive shunt which emerges at lower frequencies was shown to be equivalent to the direct current (d.c.) impedance of the interface. A Cole-Cole (1941) type of relaxation model is proposed to describe the interface behaviour over all frequency ranges. Nonlinear polarisation measurments have demonstrated the validity of Schwan’s limit law of linearity at very low frequencies.
121 citations
"A Novel Technique of Flow Measureme..." refers background in this paper
...If a very small value of sinusoidal voltage signal is applied across the electrodes, then this ac voltage signal is superimposed with the half-cell potential [8], [9] at each electrode, and accordingly, the flow of ions from one electrode to the other is obtained....
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...When two metal electrodes are immersed in a conducting liquid, the polarization effect [1], [3], [8]–[11] at each electrode produces an electric double layer at each metal liquid interface, across of which there exists a difference in potential along with a polarization impedance....
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