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Journal ArticleDOI

A low-cost noncontact capacitance-type level transducer for a conducting liquid

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
Citations
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Proceedings ArticleDOI
TL;DR: The device provides faster and more efficient separation than the traditional techniques and is designed for crude oil separation tanks and is sought to replace other traditional methods such as the ones using chemicals.
Abstract: In this paper, a new innovative closed-loop and autonomous electronic device for oil-water separation in the emulsion layer is presented The device is designed for crude oil separation tanks and is sought to replace other traditional methods such as the ones using chemicals It is modular and comprises three subsystems: sensing subsystem, actuating subsystem, and data communication/interfacing subsystem The sensing subsystem is intrinsically safe and consists of a one dimensional level array of non intrusive ultrasonic transducers that monitor in real-time the low and high levels of the emulsion layer in a tank with a vertical resolution of 15 cm The actuating system includes a microwave generator which stimulates the emulsion at a predefined position to breaks it out A built-in feedback PID-based controller determines the optimal position of this generator based on the oil-water content which is provided by the sensor array and moves the generator accordingly The data communication/interfacing system is responsible to transfer to the control room real-time data (eg the actual position of the emulsion layer and the actual temperature inside the tank) using field bus network protocol (RS485 protocol) This would help a continuous and effective monitoring by the operator using a dedicated GUI In addition of being safe and environmentally friendly, the device provides faster and more efficient separation than the traditional techniques

2 citations


Cites background from "A low-cost noncontact capacitance-t..."

  • ...The usage of capacitance devices are addressed in [1, 2, 3]....

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Proceedings ArticleDOI
01 May 2014
TL;DR: In this paper, an improved capacitance probe has been designed which has no inductance effect and the theory of operation of this sensor has been explained in the paper and the experimental results have been described in the literature.
Abstract: The liquid level is measured by different techniques of which capacitance techniques has wide application in measurement of level of aqueous solution in a storage tank by using insulated metallic rod electrode immersed in a metallic tank or two such identical electrode immersed in a non metallic tank. This measurement may suffer from inductance effect. Hence, the system likes a coaxial cable which has both inductance and capacitance effect. In the present paper an improved capacitance probe is designed which has no inductance effect. The theory of operation of this sensor has been explained in the paper. The sensor has been designed and tested experimentally. The experimental results are described in the paper. A very good linearity has been observed.

1 citations


Cites background or methods from "A low-cost noncontact capacitance-t..."

  • ...Following the same procedure as in [3], the bridge output V0 is given by,...

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  • ...In the present work a modified capacitance bridge technique [3] has been used to measure the change of capacitance of the proposed level sensor free from any self inductance effect....

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  • ...A modified De’Sauty bridge circuit [3] using op-amp is designed as shown in Fig....

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  • ...(a) Sectional view (b) Cross sectional view Now a single turn coil with conductor radius r has conductor height 2r [3]....

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Journal ArticleDOI
TL;DR: A design on the development of a new miniaturized lowcost TDR meter capable of sampling a repetitive rectangular waveform, which is used as an excitation signal, and experimental results indicate the feasibility and improved functionality of the system.
Abstract: In the radar level measurement instruments, the electromagnetic signal travel through air. Once it touches the material under test, it gets reflected back to the input end. The reflection of electromagnetic signal depends on electric and dielectric properties of material. Guided Wave Radar (GWR) meter isbased on the Time Domain Reflectrometry (TDR) principle for precise level measurement. TDR, which is well known measurement technique in telecommunication industries for evaluating electric and dielectric property of various material, used for precise level measurement and fault detection. Despite all advancement made within the last few years, there is still lack of low cost, small TDR meter equipment in market. This paper proposes a designon the development of a new miniaturized lowcost TDR meter capable of sampling a repetitive rectangular waveform, which is used as an excitation signal. The key techniques of pulse generation and time measurement are introduced with the selection of GWR probe for accuracy even when the measurement within a highly unstable environment. The signal generation with fast rising time is accomplished using small electronic circuit and the basic laboratory setup.Generally, there is a need of a high resolution, low power consuming, miniature TDR for dynamic level measurement in petrochemical, oil tank and shipbuilding industries application. Experimental results indicate the feasibility and improved functionality of the system.

1 citations

Journal ArticleDOI
TL;DR: In this article , an ultrasonic method was proposed to solve the problem of accurately measuring the thickness of oil slick using a remotely operated vehicle (ROV) as a platform, and the results showed that the average values of absolute differences between ROV's resting and running were both less than 4.0% for two transducers, a result which indicated the high measurement accuracy, repeatability, and stability of this method.
Abstract: An ultrasonic method was proposed to solve the problem of accurately measuring the thickness of oil slick using a remotely operated vehicle (ROV) as a platform. The laboratory experiments were performed to collect ultrasonic reflections from interfaces underneath oil slick during ROV’s resting and running. A new signal processing method was proposed to improve the accuracy of the thickness measurement by precisely calculating the transmit time of flight (TOF) of ultrasound within oil slick. The feasibility of this method was verified by performing eight measurements of oil slick thicknesses during ROV’s resting and running. The results showed that the average values of absolute differences between ROV’s resting and running were both less than 4.0% for two transducers, a result which indicated the high measurement accuracy, repeatability, and stability of this method. In addition, the minimum measurable thickness for each transducer was initially investigated, and the suitable transducer frequency was also determined. The ultrasonic method proposed in this article demonstrates a strong capability of measuring the thickness of thin oil slick with the high accuracy. The studies in this article would promote the development and application of this method in the oil spill response. It could possibly be developed into an applicable tool for solving the problem of measuring the thickness of oil slick in the field in the future.

1 citations

Journal ArticleDOI
TL;DR: An electronic design for a bleeding detector used with mobile linac during intraoperative radiotherapy (IORT) is presented, which consists on a readout circuit based on a De Sauty Bridge and a wireless power supply using a supercapacitor.
Abstract: An electronic design for a bleeding detector used with mobile linac during intraoperative radiotherapy (IORT) is presented. It consists on a readout circuit based on a De Sauty Bridge and a wireless power supply using a supercapacitor. The goal is the measurement of the height of fluid present in the applicator in order to avoid a misadministration dose during the irradiation process. A minimum measurement height of 5 mm is required by clinic to be confident with the selected radiation dose. The measurement circuit uses a capacitive sensor which detects variations lower than 0.1 pF. The readout circuit converts dynamic capacitance variation from the bleeding detector into an analog voltage signal. Tests have been performed with a 40 mm diameter polymethyl methacrylate applicator (PMMA) using water. Non-bevelled PMMA 0° and 45° tilted have been considered, being this the worst condition used in the clinic. The actual height of the fluid with respect to that measured by our system shows good linearity and repeatability within acceptable limits. For 0° tilted, a 2 mm height fluid detection is achieved well below the 5 mm height demanded by clinic. For 45° tilted, a 5 mm height fluid detection is achieved.

1 citations

References
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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 low-cost noncontact capacitance-t..." refers background in this paper

  • ...Index Terms—Cylindrical capacitor, error capacitance, glass tube level sensors, high-density polyethylene (HDPE) tube level sensors, liquid level measurement, modified De’ Sauty bridge, noncontact capacitive level sensor....

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Book
01 Jan 1963
TL;DR: In this article, electrical measurements and measuring instruments, Electrical measurements and measurement instruments, electrical measurement and measuring instrument, Electrical measurement and measurement instrument, electrical measurements, measuring instruments and measuring devices.
Abstract: Electrical measurements and measuring instruments , Electrical measurements and measuring instruments , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی

96 citations

Book
01 Jan 1974

94 citations

Book
01 Jan 2003
TL;DR: In this article, the authors present a detailed description of the characteristics of a flowmetering system and its application in a variety of applications, including the following: anemometers BTU Flowmeters for Heat Exchangers BTUs for Gaseous Fuels Cross-Correlation Flow Metering Elbow Taps Flow Switches Jet Deflection Flow Detectors Laminar Flow Meters, Magnetic FlowMeters, Coriolis Mass Flow-meters-Miscellaneous Mass Flowmetmers-Thermal Metering Pumps Orifices Pitot Tubes and
Abstract: GENERAL CONSIDERATIONS Flowsheet Symbols and P&I Diagrams Functional Diagrams and Function Symbols Instrument Terminology and Performance System Accuracy Uncertainty Calculations Configuring Intelligent Devices Instrument Installation Instrument Calibration Response Time and Drift Testing Redundant and Voting Systems Instrument Evaluation Binary Logic Diagrams FLOW MEASUREMENT Application and Selection Anemometers BTU Flowmeters for Heat Exchangers BTU Flowmeters for Gaseous Fuels Cross-Correlation Flow Metering Elbow Taps Flow Switches Jet Deflection Flow Detectors Laminar Flowmeters Magnetic Flowmeters Mass Flowmeters, Coriolis Mass Flowmeters-Miscellaneous Mass Flowmeters-Thermal Metering Pumps Orifices Pitot Tubes and Area Averaging Units Polyphase (Oil/Water/Gas) Flowmeters Positive-Displacement Gas Flowmeters Positive-Displacement Liquid Meters and Provers Purge Flow Regulators Segmental Wedge Flowmeter Sight Flow Indicators Solids Flowmeters and Feeders Target Meters Turbine and Other Rotary Element Flowmeters Ultrasonic Flowmeters Variable-Area, Gap, and Vane Flowmeters V-Cone Flowmeter Venturi Tubes, Flow Tubes, and Flow Nozzles Vortex and Fluidic Flowmeters Weirs and Flumes LEVEL MEASUREMENT Application and Selection Bubblers Capacitance and Radio Frequency (RF) Admittance Probes Conductivity and Field Effect Level Switches Diaphragm Level Detectors Differential Pressure Level Detectors Displacer Level Detectors Float Level Devices Laser Level Sensors Level Gauges, Including Magnetic Microwave Level Switches Optical Level Devices Radar, Noncontacting Level Sensors Radar, Contact Level Sensors (TDR, GWR, PDS) Radiation Level Sensors Resistance Tapes Rotating Paddle Switches Tank Gauges Including Float-Type Tape Gauges Thermal Level Sensors Time Domain Reflectometry and Phase Difference Sensors Ultrasonic Level Detectors Vibrating Level Switches TEMPERATURE MEASUREMENT Application and Selection Bimetallic Thermometers Calibrators and Simulators Color Indicators, Crayons, Pellets Fiber-Optic Thermometers Filled-Bulb and Glass-Stem Thermometers Integrated Circuitry (IC) Transistors and Diodes Miscellaneous Temperature Sensors Pneumatic and Suction Pyrometers Pyrometric Cones Radiation and Infrared Pyrometers Quartz Crystal Thermometry Resistance Temperature Detectors (RTDs) Temperature Switches and Thermostats Thermistors Thermocouples Thermowells Ultrasonic Thermometers PRESSURE MEASUREMENT Selection and Application Accessories: Seals, Snubbers, Calibrators, and Manifolds Bellows-Type Pressure Sensors Bourdon and Helical Pressure Sensors Diaphragm or Capsule-Type Sensors Differential Pressure Instruments Electronic Pressure Sensors High-Pressure Sensors Manometers Multiple Pressure Scanners Multiple Pressure Scanners Pressure Gauges Pressure Repeaters Pressure and Differential Pressure Switches Vacuum Sensors DENSITY MEASUREMENT Density: Applications and Selection Displacement- and Float-Type Densitometers Hydrometers Hydrostatic Densitometers Oscillating Coriolis Densitometer (Gas, Liquid, and Slurry Services) Radiation Densitometers Ultrasonic Sludge and Slurry Densitometers Liquid/Slurry/Gas Density-Vibrating Densitometers Weight-Based and Miscellaneous Densitometers Gas Densitometers SAFETY AND MISCELLANEOUS SENSORS Boroscopes Electrical and Intrinsic Safety Electrical Meters and Sensors Energy Management Devices (Peak Load Shedding) Excess Flow and Regular Check Valves Explosion Suppression and Deluge Systems Flame Arresters, Conservation Vents, and Emergency Vents Flame, Fire, and Smoke Detectors Leak Detectors Linear and Angular Position Detection Machine Vision Technology Metal Detectors Noise Sensors Proximity Sensors and Limit Switches Relief Valves-Determination of Required Capacity Relief Valves-Sizing, Specification, and Installation Rupture Discs Soft Sensors Tachometers and Angular Speed Detectors Thickness and Dimension Measurement Torque and Force Transducers Vibration, Shock, and Acceleration Weather Stations Weighing Systems: General Considerations Weight Sensors ANALYTICAL INSTRUMENTATION Analyzer Application and Selection Analyzer Sampling: Process Samples Analyzer Sampling: Stack Particulates Analyzers Operating on Electrochemical Principles Air Quality Monitoring Biometers Biochemical Oxygen Demand, Chemical Oxygen Demand, and Total Oxygen Demand Calorimeters Carbon Dioxide Carbon Monoxide Chlorine Chromatographs: Gas Chromatographs: Liquid Coal Analyzers Colorimeters Combustibles Conductivity Analyzers Consistency Analyzers Corrosion Monitoring Differential Vapor Pressure Sensor Dioxin Analysis Elemental Monitors Fiber-Optic Probes Fluoride Analyzers Hydrocarbon Analyzers Hydrogen Sulfide Infrared Analyzers Ion-Selective Electrodes Mass Spectrometers Mercury in Air Mercury in Water Moisture in Air: Humidity and Dew Point Moisture in Gases and Liquids Moisture in Solids Molecular Weight Nitrate, Ammonia, and Total Nitrogen Nitrogen Oxide Analyzers Odor Detection Oil in or on Water Open Path Spectrometry Oxidation-Reduction Potential (ORP) Oxygen in Gases Oxygen in Liquids (Dissolved Oxygen) Ozone in Gas Ozone in Water Particulates, Opacity, Dust, and Smoke Particle Size and Distribution Monitors pH Measurement Phosphorus Analyzer Physical Properties Analyzers - ASTM Methods Raman Analyzers Refractometers Rheometers Streaming Current or Particle Charge Analyzer Sulfur-in-Oil Analyzers Sulfur Oxide Analyzers Thermal Conductivity Detectors Total Carbon Analyzers Toxic Gas Monitoring Turbidity, Sludge, and Suspended Solids Ultraviolet and Visible Analyzers Viscometers-Application and Selection Viscometers-Laboratory Viscometers-Industrial Water Quality Monitoring Wet Chemistry and Autotitrator Analyzers APPENDIX International System of Units Engineering Conversion Factors Chemical Resistance of Materials Composition of Metallic and Other Materials Steam and Water Tables Friction Loss in Pipes Tank Volumes Directory of "Lost" Companies INDEX

93 citations


"A low-cost noncontact capacitance-t..." refers background in this paper

  • ...Index Terms—Cylindrical capacitor, error capacitance, glass tube level sensors, high-density polyethylene (HDPE) tube level sensors, liquid level measurement, modified De’ Sauty bridge, noncontact capacitive level sensor....

    [...]

  • ...However, this type of measuring system is much costlier than the other similar instruments....

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Journal ArticleDOI
TL;DR: In this article, a stray-immune capacitance measuring instrument based on the charge transfer principle is described, which has a programmable measurement frequency up to several megahertz and is inexpensive and suitable for integration onto a single chip.
Abstract: A stray-immune capacitance measuring instrument based on the charge transfer principle is described. It has a programmable measurement frequency up to several megahertz and is inexpensive and suitable for integration onto a single chip. The effects of stray capacitances, including those of the switching components, have been eliminated by using a special switching arrangement, resulting in a baseline drift of 0.02 pF (at 1-MHz measurement frequency) over a 12-h period. >

91 citations