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Author

Satish Chandra Bera

Other affiliations: Techno India
Bio: Satish Chandra Bera is an academic researcher from University of Calcutta. The author has contributed to research in topics: Transducer & Flow measurement. The author has an hindex of 12, co-authored 51 publications receiving 525 citations. Previous affiliations of Satish Chandra Bera include Techno India.


Papers
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Journal ArticleDOI
TL;DR: An attempt has been made to design a low-cost noncontact capacitance-type level sensor for a conducting liquid that is found to have good linearity and repeatability within acceptable limits.
Abstract: In this paper, an attempt has been made to design a low-cost noncontact capacitance-type level sensor for a conducting liquid. The sensor is in the form of a uniform circular cylinder made of insulating material like glass, ceramic, plastic, etc. The sensor is connected with the metallic- or nonmetallic-type liquid storage tank, in which the conducting liquid column is taken as one electrode, and a noninductively wound short-circuited outside coil is taken as the other electrode of a variable capacitor. The change in capacitance due to the change of liquid level is measured by a modified linear operational-amplifier-based De' Sauty bridge network with adjustable bridge sensitivity. The bridge output after amplification and rectification may be used to drive a direct current indicator calibrated in level. The studies have been made with high-density polyethylene and glass tube sensors separately in both metallic and nonmetallic storage tanks with tap water as the conducting liquid, and the experimental results of the static characteristics of the level sensors with percentage error from linearity are presented in the paper. These results are found to have good linearity and repeatability within acceptable limits

99 citations

Journal ArticleDOI
TL;DR: A modified capacitance-type liquid level sensor is presented in which effect of self-inductance of the metallic rod has been eliminated and the theoretical equations describing the operation of the sensor are derived.
Abstract: The conventional capacitance-type liquid level sensor consists of an insulated solid metallic rod electrode immersed in the liquid contained in a metallic storage tank, or two such identical electrodes in a nonmetallic storage tank. Such metallic rods may suffer from the self-inductance effect which varies nonlinearly with the level. In this paper, we present a modified capacitance-type level sensor in which effect of self-inductance of the metallic rod has been eliminated. The theoretical equations describing the operation of the sensor are derived. The sensor is designed and tested experimentally and is found to follow the theoretical equations. The experimental results are also presented. A very good linearity of the sensor is observed.

55 citations

Journal ArticleDOI
TL;DR: A modified operational-amplifier-based Maxwell-Wien bridge measurement technique has been proposed in which the effect of stray capacitance and inductance is minimized and linear characteristics over a wide range of displacement with good repeatability, linearity, and variable sensitivity have been described.
Abstract: The small inductance of an inductive transducer generally linearly changes with a process variable, but their measurement by the usual inductive bridge circuit like the Maxwell bridge, the Maxwell-Wien Bridge, the Hay bridge, etc., suffers from errors due to the effect of the stray capacitance between bridge nodal points and the ground and the stray inductance on the inductive coil, respectively. The conventional Wagner-Earth technique is not suitable for continuous measurement. In this paper, a modified operational-amplifier-based Maxwell-Wien bridge measurement technique has been proposed in which the effect of stray capacitance and inductance is minimized. In the first phase of the experiment, the bridge performance has been studied with a known variable inductor, and in the second phase, the same experimentation was done by replacing the variable inductor with an inductive coil having an adjustable core position for the measurement of displacement. The linear characteristics over a wide range of displacement with good repeatability, linearity, and variable sensitivity have been described.

36 citations

Journal ArticleDOI
TL;DR: In the proposed transducer, the use of a diaphragm-type DP cell is not needed, and thus, the problems associated with DP cell are avoided.
Abstract: The ordinary orifice transducer widely used in process industries for flow rate measurement produces a differential pressure which is generally measured by a DP cell and thus may suffer from various problems like leakage of process fluid, corrosion of diaphragm materials, etc In this paper, the design of a noncontact capacitance-type orifice transducer for the measurement of flow rate of a conducting liquid through a pipeline has been described In the proposed transducer, the use of a diaphragm-type DP cell is not needed, and thus, the problems associated with DP cell are avoided The theoretical analysis of the flow transducer is presented in this paper The performance of the flow transducer along with that of the signal conditioner for flow of tap water through a pipeline has been tested experimentally The experimental results are presented in this paper A good linearity and repeatability of the sensor capacitance, transducer output, and signal conditioner output with flow rate have been observed

33 citations

Journal ArticleDOI
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.

33 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, a digital light processing (DLP®) based 3D printing technique was explored to manufacture electrically conductive objects of polymer nanocomposites, where the ink was made of a mixture of photocurable resin with multi-walled carbon nanotubes (MWCNTs).
Abstract: 3D printing has gained significant research interest recently for directly manufacturing 3D components and structures for use in a variety of applications. In this paper, a digital light processing (DLP®) based 3D printing technique was explored to manufacture electrically conductive objects of polymer nanocomposites. Here, the ink was made of a mixture of photocurable resin with multi-walled carbon nanotubes (MWCNTs). The concentrations of MWCNT as well as the printing parameters were investigated to yield optimal conductivity and printing quality. We found that 0.3 wt% loading of MWCNT in the resin matrix can provide the maximum electrical conductivity of 0.027S/m under the resin viscosity limit that allows high printing quality. With electric conductivity, the printed MWCNT nanocomposites can be used as smart materials and structures with strain sensitivity and shape memory effect. We demonstrate that the printed conductive complex structures as hollow capacitive sensor, electrically activated shape memory composites, stretchable circuits, showing the versatility of DLP® 3D printing for conductive complex structures. In addition, mechanical tests showed that the addition of MWCNT could slightly increase the modulus and ultimate tensile stress while decreasing slightly the ultimate stretch, indicating that the new functionality is not obtained at the price of sacrificing mechanical properties.

246 citations

Journal ArticleDOI
TL;DR: In this paper, a brief overview of traditional methods of measurement of electric current and some relatively new types of current sensors are discussed, including Hall sensors with field concentrators, AMR current sensors, magneto-optical and superconducting current sensors.
Abstract: The review makes a brief overview of traditional methods of measurement of electric current and shows in more detail relatively new types of current sensors. These include Hall sensors with field concentrators, AMR current sensors, magneto-optical and superconducting current sensors. The influence of the magnetic core properties on the error of the current transformer shows why nanocrystalline materials are so advantageous for this application. Built-in CMOS current sensors are important tools for monitoring the health of integrated circuits. Of special industrial value are current clamps which can be installed without breaking the measured conductor. Parameters of current sensors are also discussed, including geometrical selectivity. This parameter specific for current sensors means the ability to suppress the influence of currents external to the sensor (including the position of the return conductor) and also suppress the influence on the position of the measured conductor with respect to the current.

210 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe the design and implementation of a liquid-level measurement system based on a remote grounded capacitive sensor, which relies on a simple relaxation oscillator and a microcontroller.
Abstract: This paper describes the design and implementation of a liquid-level measurement system based on a remote grounded capacitive sensor. The electrodes of the capacitive sensor are built with affordable materials: a rod of stainless steel and a PTFE-insulated wire. The interface circuit relies on a simple relaxation oscillator and a microcontroller. A cable with active shielding interconnects the sensor to the interface circuit. The stability of the active-shielding circuit is analysed by taking into account the parasitic components of both the interconnecting cable and the sensor. The system has been experimentally tested by measuring the level of tap water in a grounded metallic container. Over a level range of 70 cm, the system has a non-linearity error smaller than 0.35 mm and a resolution better than 0.10 mm for a measuring time of 20 ms.

157 citations

Journal ArticleDOI
TL;DR: A water level measurement using an interdigital capacitive sensor with low-cost, low-energy, good repeatability, high linearity, and ease of installation is proposed with a support of experimental results.
Abstract: A water level measurement using an interdigital capacitive sensor with low-cost, low-energy, good repeatability, high linearity, and ease of installation is proposed with a support of experimental results. This sensor comprises a printed circuit board (PCB) with configuration of two interpenetrating comb electrodes. The comb electrode is 70–80 mm width, 300 mm height with 1–2 mm spacing between each comb. This configuration of electrode causes the capacitance between comb electrodes to vary by the water level. Microcontroller is used to calculate the capacitance between comb electrodes in terms of a discharge time correlated to the water level. A practical water level measurement technique using two comb electrodes designated as level and reference sensors is presented. This technique can directly be applied to water with different conditions without recalibration. This sensor is able to measure absolute levels of water with 0.2 cm resolution over 30 cm range. In addition, it is also sensitive enough to trace the variability of water level. A flood monitoring simulation is carried out in wave flume where this sensor is used to detect the rising wave.

128 citations

Journal ArticleDOI
TL;DR: In this paper, electric field induced director orientation of a nematic liquid crystal (LC)+ carbon nanotube (CNT) system reveals insights on switching behavior for this anisotropic composite.
Abstract: Electric field induced director orientation of a nematic liquid crystal (LC)+carbon nanotube (CNT) system reveals insights on switching behavior for this anisotropic composite. Once the field goes off, the LC+CNT system relaxes back to the original orientation through a mechanical rotation, revealing the intrinsic dynamics. LC molecules and CNTs cooperatively form local pseudonematic domains in the isotropic phase due to strong LC-CNT interactions. These field-responsive anisotropic domains do not relax back to the original orientation on switching of the field off, which could find potential applications in memory devices.

99 citations