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
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TL;DR: In this paper , a supplyvoltage driving (SVDR) scheme for capacitive sensor front-ends is proposed to eliminate the parasitic capacitance effects, which is intended for remote sensors connected to the circuit through a shielded cable.
Abstract: In this article, a novel supply-voltage driving (SVDR) scheme for capacitive sensor front-ends is proposed to eliminate the parasitic capacitance effects. The suggested circuit is intended for remote sensors (and, hence, connected to the circuit through a shielded cable) with one electrode grounded and of low capacitance (in the 0–10-pF range). The effects of the parasitic capacitance of the cable are avoided using the active-shielding technique, whereas those of the amplifier input through a smart driving of the reference node of the amplifier supply voltage. Thanks to these techniques, the input–output characteristic shows, without applying any adjustment and/or calibration, an offset error lower than 3 fF. The nonlinearity error (NLE) is in the order of 0.01% of the full-scale span (FSS), which corresponds to 1 fF. Different operational amplifiers (OAs) and different lengths (up to 15 m) of the interconnecting cable are experimentally tested to demonstrate the feasibility of the circuit. In comparison with similar circuits recently suggested in the literature, the proposed circuit does not require any bulky component, such as a transformer, and consequently, it is a lower-cost solution and suitable to be integrated.
TL;DR: In this paper, a simple design of a short-range non-inductive capacitance-type level sensor which is developed for closed tanks (like fuel tanks of vehicles) is proposed.
Abstract: In this paper, a simple design of a short-range non-inductive capacitance-type level sensor which is developed for closed tanks (like fuel tanks of vehicles) is proposed. The level sensor is analyt...
01 Jan 2012
TL;DR: In this paper, a water level sensor fabricated from a printed circuit board was presented, which measured the change of capacitance between parallel fingers according to the water level and converted it to water level by a microcontroller.
Abstract: This paper presents the water level sensor fabricated from a printed circuit board. The copper traces of a printed circuit board as periodic fingers and capacitance between parallel fingers varied according to the water level. The change of capacitance can be measured and converted to a water level by a microcontroller. The output signal of a water level from a microcontroller transmitted to a computer or other devices are compatible with the RS-232 standard. The experimental results show that the water level sensor has linear relation with R 2 = 0.9992 and maximum error is 2.3 %FSO. In addition, this sensor need low energy.
01 Jan 2021
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 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....
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...However, this type of measuring system is much costlier than the other similar instruments....
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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