This document discusses the measurement of pressure, velocity, and flow. It begins with an overview of measuring pressure and velocity, as pressure measurements can be used to obtain velocity. Key relationships between pressure and velocity are explained, such as Bernoulli's equation. Common pressure measurement devices are then described, including manometers, which use liquid columns, and electromechanical transducers like Bourdon tubes. The response of these devices and considerations for measurement ranges are also covered. Finally, the document discusses the differences between measuring flow rate versus velocity and different units used to express these quantities.
This document provides an overview of pressure instrumentation and process control. It discusses various methods of pressure measurement including manometers, elastic pressure transducers like Bourdon tubes, diaphragms and bellows, as well as electrical pressure transducers. It also covers topics like measurement of vacuum using instruments like the McLeod gauge and thermal conductivity gauge. Maintaining and calibrating pressure measuring instruments is important for accurate process measurement and control.
The document discusses different types of pressure measurement techniques including manometers, elastic sensors like Bourdon tubes, and calibration using a dead weight tester. It explains how manometers like the U-tube manometer and well manometer measure pressure as a difference or height of fluid columns. Bourdon tubes are elastic tubes that deform under pressure and transmit the measurement mechanically. A dead weight tester precisely applies known pressures using weights on a floating piston to calibrate other pressure sensors.
Flow sensors measure the rate of fluid flow through pipes. The key properties affecting fluid flow are velocity, pipe size, friction, viscosity, specific gravity, and fluid condition. Measuring flow is important for process control and efficiency. Common types of flow meters include differential pressure meters (orifice, venturi, nozzle), Coriolis, vortex, ultrasonic, electromagnetic, and thermal meters. Each works on different principles and has advantages and limitations for different applications.
This document provides an overview of instrumentation and process control. It defines key terms like instrumentation, process, transducer, signal, loop, controller, and interlock. It describes common process parameters measured like pressure, level, temperature, and flow. It discusses primary measuring devices and principles for each process variable. It also covers control valves and automation systems like DCS, PLC, and SCADA.
Pressure measurement wiki lesker pumping 3_6_09 (2)shivanand swami
This document discusses various methods and instruments used to measure pressure. It describes different types of pressure measurements including absolute pressure, gauge pressure, and differential pressure. It then explains several common pressure measurement instruments such as manometers, piston gauges, bourdon gauges, and diaphragm gauges. The document also discusses thermal conductivity gauges like Pirani gauges, as well as ionization gauges and how they work. Finally, it provides an overview of various vacuum pump technologies including rotary vane pumps, scroll pumps, diffusion pumps, turbomolecular pumps, and cryopumps.
Pressure is a key process variable measured in many industrial applications. Common mechanical pressure sensors include diaphragms, pressure springs like Bourdon tubes, and bellows, which flex or move in response to pressure changes. A manometer is a simple device that measures pressure by the movement of a liquid column in a tube. Common types are U-tube, inclined tube, and well manometers. Manometers measure pressure in terms of liquid height based on density and specific gravity.
This document discusses various types of pressure measurement. It defines pressure and units like pascals and atmospheres. Static pressure is exerted by stationary fluids while dynamic pressure results from moving fluids. Absolute pressure is measured against a vacuum and gauge pressure against atmospheric pressure. Hydrostatic pressure increases with depth in liquids. Common pressure measurement instruments include manometers, elastic elements like bourdon tubes, and electrical resistance gauges. Low pressures are measured using McLeod, Pirani, and ionization gauges. Selection depends on the pressure range, accuracy needed, and other factors like cost and maintenance.
This document provides an overview of pressure instrumentation and process control. It discusses various methods of pressure measurement including manometers, elastic pressure transducers like Bourdon tubes, diaphragms and bellows, as well as electrical pressure transducers. It also covers topics like measurement of vacuum using instruments like the McLeod gauge and thermal conductivity gauge. Maintaining and calibrating pressure measuring instruments is important for accurate process measurement and control.
The document discusses different types of pressure measurement techniques including manometers, elastic sensors like Bourdon tubes, and calibration using a dead weight tester. It explains how manometers like the U-tube manometer and well manometer measure pressure as a difference or height of fluid columns. Bourdon tubes are elastic tubes that deform under pressure and transmit the measurement mechanically. A dead weight tester precisely applies known pressures using weights on a floating piston to calibrate other pressure sensors.
Flow sensors measure the rate of fluid flow through pipes. The key properties affecting fluid flow are velocity, pipe size, friction, viscosity, specific gravity, and fluid condition. Measuring flow is important for process control and efficiency. Common types of flow meters include differential pressure meters (orifice, venturi, nozzle), Coriolis, vortex, ultrasonic, electromagnetic, and thermal meters. Each works on different principles and has advantages and limitations for different applications.
This document provides an overview of instrumentation and process control. It defines key terms like instrumentation, process, transducer, signal, loop, controller, and interlock. It describes common process parameters measured like pressure, level, temperature, and flow. It discusses primary measuring devices and principles for each process variable. It also covers control valves and automation systems like DCS, PLC, and SCADA.
Pressure measurement wiki lesker pumping 3_6_09 (2)shivanand swami
This document discusses various methods and instruments used to measure pressure. It describes different types of pressure measurements including absolute pressure, gauge pressure, and differential pressure. It then explains several common pressure measurement instruments such as manometers, piston gauges, bourdon gauges, and diaphragm gauges. The document also discusses thermal conductivity gauges like Pirani gauges, as well as ionization gauges and how they work. Finally, it provides an overview of various vacuum pump technologies including rotary vane pumps, scroll pumps, diffusion pumps, turbomolecular pumps, and cryopumps.
Pressure is a key process variable measured in many industrial applications. Common mechanical pressure sensors include diaphragms, pressure springs like Bourdon tubes, and bellows, which flex or move in response to pressure changes. A manometer is a simple device that measures pressure by the movement of a liquid column in a tube. Common types are U-tube, inclined tube, and well manometers. Manometers measure pressure in terms of liquid height based on density and specific gravity.
This document discusses various types of pressure measurement. It defines pressure and units like pascals and atmospheres. Static pressure is exerted by stationary fluids while dynamic pressure results from moving fluids. Absolute pressure is measured against a vacuum and gauge pressure against atmospheric pressure. Hydrostatic pressure increases with depth in liquids. Common pressure measurement instruments include manometers, elastic elements like bourdon tubes, and electrical resistance gauges. Low pressures are measured using McLeod, Pirani, and ionization gauges. Selection depends on the pressure range, accuracy needed, and other factors like cost and maintenance.
1) Accurate measurement of flow rates is important for maintaining quality in industrial processes, as most control loops regulate incoming flows.
2) Common types of flowmeters include obstruction, inferential, electromagnetic, ultrasonic, anemometer, and Coriolis mass flowmeters.
3) Obstruction flowmeters like orifice plates and venturi tubes create a restriction to induce a pressure drop related to flow rate.
Flow is defined as the volume of material passing a specific place in a specified time interval. Common units of flow include gallons per minute, cubic feet per second, and tons per hour. Flow can be measured directly by measuring the volume passing over time, or indirectly by measuring changes in velocity, depth, or pressure and relating these to flow rate using primary and secondary measuring devices. Positive displacement meters and differential pressure meters are common types of flow measurement systems. Selection of a flow meter depends on factors like required accuracy, pressure loss, material properties, cost, and ease of installation and use.
In this presentation how flow rate, pressure, temperature and level in tank measure in refinery or any industry with different instrument are discussed.
ROLE OF CONTROL AND INSTRUMENTATION IN THERMAL POWER PLANTGaurav Rai
Role of control and instrumentation in thermal power plant.
Use of various instruments for the measurements of flow, pressure and temperature in industries.
This document defines various types of pressure and units of pressure measurement. It describes how pressure is measured using mechanical devices like manometers, bourdon tubes, and diaphragms. Absolute, gauge, differential, and other pressures are defined. Common units include psi, kPa, inches of water and mercury. Pressure results from force over an area and is proportional to height and density of the fluid. Mechanical pressure sensors are converted to electrical signals using transducers like potentiometers and capacitors.
This document discusses various transducers used for pressure, temperature, level, and flow measurements. It describes different pressure measurement units and scales including absolute, gauge, differential, atmospheric, and vacuum pressure scales. Common pressure transducers like Bourdon gauges and capacitive transducers are explained. Temperature measurement principles of liquid-in-glass thermometers and rotary thermometers are outlined. Common temperature transducers like thermocouples, RTDs, and thermistors are also summarized along with the working principle of thermocouples based on the Seebeck effect.
The document discusses various methods for measuring pressure, including diaphragms, bourdon tubes, capsules, and different transduction methods like potentiometric, strain gauge, variable reluctance, LVDT, variable capacitance, and piezoelectric devices. It also covers topics like pressure multiplexers, calibration using dead weight testers, and force balance transducers using feedback principles. Piezoelectric transducers use materials that generate voltage under mechanical stress, with quartz and ceramics being common choices.
Low pressure system in anaesthesia machineSwadheen Rout
This document provides information about Boyle's anesthesia machine. It discusses the components and functions of an anesthesia machine, including the pneumatic and electrical systems. It describes the different parts of the machine like the flowmeters, vaporizers, check valves, and safety features. The document explains how flowmeters work using the Hagen-Poiseuille equation and factors like viscosity, density, and laminar vs turbulent flow. It discusses temperature and pressure effects on flowmeters as well as protections against delivering a hypoxic gas mixture to the patient.
This document provides an overview of various sensors and transducers used to measure physical quantities like temperature, pressure, force, displacement, acceleration, torque, and level. It describes the construction and working principles of resistive temperature detectors (RTDs), thermistors, strain gauges, pressure sensors using diaphragms and bellows, linear variable differential transformers (LVDTs), and capacitive and float-based level transducers. Measurement techniques for pressure, force, acceleration, and torque using springs, load cells, and twisting rods are also summarized. The document aims to educate readers on commonly used sensors and transducers in industrial instrumentation and control applications.
Mechanical devices like bellows, diaphragms, and bourdon tubes are used as primary sensing elements that convert physical quantities like pressure into mechanical motion. Transducers are then used to convert this mechanical motion into an electrical signal. Transducers can be classified based on their physical effect, measured physical quantity, or energy source. Key characteristics like accuracy, sensitivity, range, and reliability must be considered when selecting a transducer for a particular application.
(1) Pressure is defined as force divided by area and can be exerted by solids, liquids, and gases. Common pressure units include Pa, psi, atm, bar, and torr. (2) Static pressure is exerted by stationary fluids and gases while dynamic pressure is exerted by moving fluids due to impact. (3) Absolute pressure is measured relative to a vacuum while gauge pressure is measured relative to atmospheric pressure. Hydrostatic pressure in liquids increases with depth due to weight. (4) Common pressure measurement instruments include manometers, elastic elements like bourdon tubes, and electrical resistance, McLeod, Pirani, and ionization gauges for varying pressure ranges.
Pressure can be measured using various instruments that operate based on different principles. Manometers like U-tube and inclined manometers measure pressure using the height of liquid columns. Bourdon tube, diaphragm, and bellows gauges use mechanical elements that deform under pressure. Piezoelectric sensors generate electrical signals in response to applied pressure. Proper instrument selection depends on the type of pressure (absolute, gauge, or vacuum), required accuracy, and application. Common applications include fluid system monitoring, HVAC, boilers, and automotive/medical uses.
The document discusses various types of pressure measurement instruments and concepts. It describes pressure gauges, transmitters, and transducers, explaining their measuring principles, components, installation considerations, and common terms. Diagrams illustrate typical configurations and components of differential pressure transmitters and loops.
1) Flow measurement devices use principles like differential pressure and velocity to measure flow rate. Differential pressure devices like Venturi meters and orifice plates cause a pressure drop that is measured to calculate flow.
2) Bernoulli's equation relates pressure, velocity, and height of a fluid flowing through a pipe. It is the basis for differential pressure flow measurement. Devices like Pitot tubes and turbine meters measure velocity which relates to flow rate.
3) Vibration is oscillatory motion that can be caused by unbalanced forces, elasticity, or external excitation. It can have harmful or beneficial effects depending on the system. Measurement devices like vibrometers and accelerometers are used to characterize vibrations.
Fluke Calibration Tips for High Pressure CalibrationTranscat
In this presentation, you’ll learn about:
• Physics principles that impact high-pressure calibration
• Appropriate calibration tools
• Different tips and techniques to simplify and improve the
quality of high-pressure calibrations
1. Pressure can be measured using various instruments including manometers, bourdon tube pressure gauges, and electrical pressure transducers.
2. Bourdon tube pressure gauges measure pressure by using the deflection of an elliptical bourdon tube, while diaphragm pressure transducers measure the deflection of a thin metal diaphragm.
3. Electrical pressure transducers convert the mechanical deflection or strain measurement into an electrical signal using various methods including resistance strain gauges, capacitive sensors, and piezoelectric crystals.
This document provides an overview of fluid statics and pressure measurement. It defines key concepts like pressure, absolute and gauge pressure, and buoyancy. It also gives examples of pressure measurement devices like piezometers, manometers (simple, multi-fluid, and differential), and bourdon gauges. Sample problems demonstrate calculating pressure at various depths and interfaces between fluids, as well as buoyant forces and fractional submersion of objects based on fluid densities. The goal is for students to understand fluid statics, pressure characteristics, and how to measure pressure using different techniques.
This document discusses different types of pressure sensors. It begins by explaining how pressure is commonly measured in absolute or gauge terms. It then describes various mechanical and electrical methods for pressure measurement, including elastic pressure transducers like Bourdon tubes, diaphragms, and bellows, as well as electric methods using strain gauges, capacitance, piezoelectricity, and resonant wires. Specific types of sensors are then explained in more detail, such as how strain gauges and capacitive sensors detect pressure changes. The document concludes by noting factors like process conditions, pressure range, and required sensitivity that influence the selection of an appropriate pressure sensor.
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page .docxjoyjonna282
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page 2
2
ME495—Thermo Fluids Laboratory
~~~~~~~~~~~~~~
PIPE FLOW CHARACTERISTICS
AND PRESSURE TRANSDUCER
CALIBRATION
~~~~~~~~~~~~~~
PREPARED BY: GROUP LEADER’S NAME
LAB PARTNERS: NAME
NAME
NAME
TIME/DATE OF EXPERIMENT: TIME , DATE
~~~~~~~~~~~~~~
OBJECTIVE— The objectives of this experiment are
to: a) observe the characteristics of flow in a pipe,
b) evaluate the flow rate in a pipe using velocity
and pressure difference measurements, and c)
perform the calibration of a pressure transducer.
Upon completing this experiment you should have
learned (i) how to measure the flow rate and average
velocity in a pipe using a Pitot tube and/or a resistance
flow meter, and (ii) how to classify the general
characteristics of a pipe flow.
Nomenclature
a = speed of sound, m/s
A = area, m
2
C = discharge coefficient, dimensionless
d = pipe diameter, m
d0 = orifice diameter, m
E = velocity approach factor, dimensionless
f = Darcy friction factor, dimensionless
K0 = flow coefficient, dimensionless
k = ratio of specific heats (cp/cv), dimensionless
L = length of pipe, m
M = Mach number, dimensionless
p = pressure, Pa
p0 = stagnation pressure, Pa
p1, p2 = pressure at two axial locations along a
pipe, Pa
Q = volumetric flow rate, m
3
/s
R = specific gas constant, J·kg/K
Re = Reynolds number, dimensionless
T = temperature, K
V = local velocity, m/s
V = average velocity, m/s
Y = adiabatic expansion factor, dimensionless
= ratio of orifice diameter to pipe diameter,
dimensionless
p = pressure drop across an orifice meter, Pa
= dynamic viscosity, Pa·s
= air density, kg/m3
INTRODUCTION— The flow of a fluid (liquid or
gas) through pipes or ducts is a common part of many
engineering systems. Household applications include
the flow of water in copper pipes, the flow of natural
gas in steel pipes, and the flow of heated air through
metal ducts of rectangular cross-section in a forced-air
furnace system. Industrial applications range from the
flow of liquid plastics in a manufacturing plant, to the
flow of yogurt in a food-processing plant. Because the
purpose of a piping system is to transport a desired
quantity of fluid, it is important to understand the
various methods of measuring the flow rate.
In order to work with a fluid system, and certainly to
design a fluid system that will deliver a prescribed
flow, it is necessary to understand certain fundamental
aspects of the fluid flow. For this, one should be able
to answer questions like: Are compressibility effects
important? Is the flow laminar or turbulent? Is the
viscosity of the fluid important or not? Is the flow
steady or varying with time? What are the primary
forces of importance? For internal ...
LE03 The silicon substrate and adding to itPart 2.pptxKhalil Alhatab
The document discusses various techniques for adding layers to a silicon substrate, including oxidation, evaporation, sputtering, chemical vapor deposition, and others. It provides details on oxidation methods like dry versus wet oxidation. Thermal oxidation involves diffusing oxygen through existing oxide to form new oxide in a time-dependent process described by the Deal-Grove model. Physical vapor deposition techniques like evaporation and sputtering are also line-of-sight methods for depositing thin films. Assignment questions provide examples of calculating oxide growth times and thicknesses using the Deal-Grove model.
The document summarizes lectures on optimization of design problems in engineering. It discusses using MATLAB functions like fminbnd, fminsearch, and fminunc for single-variable and multivariable unconstrained optimization. It also discusses using fmincon for constrained optimization and provides examples of optimizing maximum shear stress, column design for minimum mass, and flywheel design for minimum mass. Analytical gradients can be provided to fmincon or it uses numerical gradients via finite differences.
1) Accurate measurement of flow rates is important for maintaining quality in industrial processes, as most control loops regulate incoming flows.
2) Common types of flowmeters include obstruction, inferential, electromagnetic, ultrasonic, anemometer, and Coriolis mass flowmeters.
3) Obstruction flowmeters like orifice plates and venturi tubes create a restriction to induce a pressure drop related to flow rate.
Flow is defined as the volume of material passing a specific place in a specified time interval. Common units of flow include gallons per minute, cubic feet per second, and tons per hour. Flow can be measured directly by measuring the volume passing over time, or indirectly by measuring changes in velocity, depth, or pressure and relating these to flow rate using primary and secondary measuring devices. Positive displacement meters and differential pressure meters are common types of flow measurement systems. Selection of a flow meter depends on factors like required accuracy, pressure loss, material properties, cost, and ease of installation and use.
In this presentation how flow rate, pressure, temperature and level in tank measure in refinery or any industry with different instrument are discussed.
ROLE OF CONTROL AND INSTRUMENTATION IN THERMAL POWER PLANTGaurav Rai
Role of control and instrumentation in thermal power plant.
Use of various instruments for the measurements of flow, pressure and temperature in industries.
This document defines various types of pressure and units of pressure measurement. It describes how pressure is measured using mechanical devices like manometers, bourdon tubes, and diaphragms. Absolute, gauge, differential, and other pressures are defined. Common units include psi, kPa, inches of water and mercury. Pressure results from force over an area and is proportional to height and density of the fluid. Mechanical pressure sensors are converted to electrical signals using transducers like potentiometers and capacitors.
This document discusses various transducers used for pressure, temperature, level, and flow measurements. It describes different pressure measurement units and scales including absolute, gauge, differential, atmospheric, and vacuum pressure scales. Common pressure transducers like Bourdon gauges and capacitive transducers are explained. Temperature measurement principles of liquid-in-glass thermometers and rotary thermometers are outlined. Common temperature transducers like thermocouples, RTDs, and thermistors are also summarized along with the working principle of thermocouples based on the Seebeck effect.
The document discusses various methods for measuring pressure, including diaphragms, bourdon tubes, capsules, and different transduction methods like potentiometric, strain gauge, variable reluctance, LVDT, variable capacitance, and piezoelectric devices. It also covers topics like pressure multiplexers, calibration using dead weight testers, and force balance transducers using feedback principles. Piezoelectric transducers use materials that generate voltage under mechanical stress, with quartz and ceramics being common choices.
Low pressure system in anaesthesia machineSwadheen Rout
This document provides information about Boyle's anesthesia machine. It discusses the components and functions of an anesthesia machine, including the pneumatic and electrical systems. It describes the different parts of the machine like the flowmeters, vaporizers, check valves, and safety features. The document explains how flowmeters work using the Hagen-Poiseuille equation and factors like viscosity, density, and laminar vs turbulent flow. It discusses temperature and pressure effects on flowmeters as well as protections against delivering a hypoxic gas mixture to the patient.
This document provides an overview of various sensors and transducers used to measure physical quantities like temperature, pressure, force, displacement, acceleration, torque, and level. It describes the construction and working principles of resistive temperature detectors (RTDs), thermistors, strain gauges, pressure sensors using diaphragms and bellows, linear variable differential transformers (LVDTs), and capacitive and float-based level transducers. Measurement techniques for pressure, force, acceleration, and torque using springs, load cells, and twisting rods are also summarized. The document aims to educate readers on commonly used sensors and transducers in industrial instrumentation and control applications.
Mechanical devices like bellows, diaphragms, and bourdon tubes are used as primary sensing elements that convert physical quantities like pressure into mechanical motion. Transducers are then used to convert this mechanical motion into an electrical signal. Transducers can be classified based on their physical effect, measured physical quantity, or energy source. Key characteristics like accuracy, sensitivity, range, and reliability must be considered when selecting a transducer for a particular application.
(1) Pressure is defined as force divided by area and can be exerted by solids, liquids, and gases. Common pressure units include Pa, psi, atm, bar, and torr. (2) Static pressure is exerted by stationary fluids and gases while dynamic pressure is exerted by moving fluids due to impact. (3) Absolute pressure is measured relative to a vacuum while gauge pressure is measured relative to atmospheric pressure. Hydrostatic pressure in liquids increases with depth due to weight. (4) Common pressure measurement instruments include manometers, elastic elements like bourdon tubes, and electrical resistance, McLeod, Pirani, and ionization gauges for varying pressure ranges.
Pressure can be measured using various instruments that operate based on different principles. Manometers like U-tube and inclined manometers measure pressure using the height of liquid columns. Bourdon tube, diaphragm, and bellows gauges use mechanical elements that deform under pressure. Piezoelectric sensors generate electrical signals in response to applied pressure. Proper instrument selection depends on the type of pressure (absolute, gauge, or vacuum), required accuracy, and application. Common applications include fluid system monitoring, HVAC, boilers, and automotive/medical uses.
The document discusses various types of pressure measurement instruments and concepts. It describes pressure gauges, transmitters, and transducers, explaining their measuring principles, components, installation considerations, and common terms. Diagrams illustrate typical configurations and components of differential pressure transmitters and loops.
1) Flow measurement devices use principles like differential pressure and velocity to measure flow rate. Differential pressure devices like Venturi meters and orifice plates cause a pressure drop that is measured to calculate flow.
2) Bernoulli's equation relates pressure, velocity, and height of a fluid flowing through a pipe. It is the basis for differential pressure flow measurement. Devices like Pitot tubes and turbine meters measure velocity which relates to flow rate.
3) Vibration is oscillatory motion that can be caused by unbalanced forces, elasticity, or external excitation. It can have harmful or beneficial effects depending on the system. Measurement devices like vibrometers and accelerometers are used to characterize vibrations.
Fluke Calibration Tips for High Pressure CalibrationTranscat
In this presentation, you’ll learn about:
• Physics principles that impact high-pressure calibration
• Appropriate calibration tools
• Different tips and techniques to simplify and improve the
quality of high-pressure calibrations
1. Pressure can be measured using various instruments including manometers, bourdon tube pressure gauges, and electrical pressure transducers.
2. Bourdon tube pressure gauges measure pressure by using the deflection of an elliptical bourdon tube, while diaphragm pressure transducers measure the deflection of a thin metal diaphragm.
3. Electrical pressure transducers convert the mechanical deflection or strain measurement into an electrical signal using various methods including resistance strain gauges, capacitive sensors, and piezoelectric crystals.
This document provides an overview of fluid statics and pressure measurement. It defines key concepts like pressure, absolute and gauge pressure, and buoyancy. It also gives examples of pressure measurement devices like piezometers, manometers (simple, multi-fluid, and differential), and bourdon gauges. Sample problems demonstrate calculating pressure at various depths and interfaces between fluids, as well as buoyant forces and fractional submersion of objects based on fluid densities. The goal is for students to understand fluid statics, pressure characteristics, and how to measure pressure using different techniques.
This document discusses different types of pressure sensors. It begins by explaining how pressure is commonly measured in absolute or gauge terms. It then describes various mechanical and electrical methods for pressure measurement, including elastic pressure transducers like Bourdon tubes, diaphragms, and bellows, as well as electric methods using strain gauges, capacitance, piezoelectricity, and resonant wires. Specific types of sensors are then explained in more detail, such as how strain gauges and capacitive sensors detect pressure changes. The document concludes by noting factors like process conditions, pressure range, and required sensitivity that influence the selection of an appropriate pressure sensor.
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page .docxjoyjonna282
Rev. August 2014 ME495 - Pipe Flow Characteristics… Page 2
2
ME495—Thermo Fluids Laboratory
~~~~~~~~~~~~~~
PIPE FLOW CHARACTERISTICS
AND PRESSURE TRANSDUCER
CALIBRATION
~~~~~~~~~~~~~~
PREPARED BY: GROUP LEADER’S NAME
LAB PARTNERS: NAME
NAME
NAME
TIME/DATE OF EXPERIMENT: TIME , DATE
~~~~~~~~~~~~~~
OBJECTIVE— The objectives of this experiment are
to: a) observe the characteristics of flow in a pipe,
b) evaluate the flow rate in a pipe using velocity
and pressure difference measurements, and c)
perform the calibration of a pressure transducer.
Upon completing this experiment you should have
learned (i) how to measure the flow rate and average
velocity in a pipe using a Pitot tube and/or a resistance
flow meter, and (ii) how to classify the general
characteristics of a pipe flow.
Nomenclature
a = speed of sound, m/s
A = area, m
2
C = discharge coefficient, dimensionless
d = pipe diameter, m
d0 = orifice diameter, m
E = velocity approach factor, dimensionless
f = Darcy friction factor, dimensionless
K0 = flow coefficient, dimensionless
k = ratio of specific heats (cp/cv), dimensionless
L = length of pipe, m
M = Mach number, dimensionless
p = pressure, Pa
p0 = stagnation pressure, Pa
p1, p2 = pressure at two axial locations along a
pipe, Pa
Q = volumetric flow rate, m
3
/s
R = specific gas constant, J·kg/K
Re = Reynolds number, dimensionless
T = temperature, K
V = local velocity, m/s
V = average velocity, m/s
Y = adiabatic expansion factor, dimensionless
= ratio of orifice diameter to pipe diameter,
dimensionless
p = pressure drop across an orifice meter, Pa
= dynamic viscosity, Pa·s
= air density, kg/m3
INTRODUCTION— The flow of a fluid (liquid or
gas) through pipes or ducts is a common part of many
engineering systems. Household applications include
the flow of water in copper pipes, the flow of natural
gas in steel pipes, and the flow of heated air through
metal ducts of rectangular cross-section in a forced-air
furnace system. Industrial applications range from the
flow of liquid plastics in a manufacturing plant, to the
flow of yogurt in a food-processing plant. Because the
purpose of a piping system is to transport a desired
quantity of fluid, it is important to understand the
various methods of measuring the flow rate.
In order to work with a fluid system, and certainly to
design a fluid system that will deliver a prescribed
flow, it is necessary to understand certain fundamental
aspects of the fluid flow. For this, one should be able
to answer questions like: Are compressibility effects
important? Is the flow laminar or turbulent? Is the
viscosity of the fluid important or not? Is the flow
steady or varying with time? What are the primary
forces of importance? For internal ...
LE03 The silicon substrate and adding to itPart 2.pptxKhalil Alhatab
The document discusses various techniques for adding layers to a silicon substrate, including oxidation, evaporation, sputtering, chemical vapor deposition, and others. It provides details on oxidation methods like dry versus wet oxidation. Thermal oxidation involves diffusing oxygen through existing oxide to form new oxide in a time-dependent process described by the Deal-Grove model. Physical vapor deposition techniques like evaporation and sputtering are also line-of-sight methods for depositing thin films. Assignment questions provide examples of calculating oxide growth times and thicknesses using the Deal-Grove model.
The document summarizes lectures on optimization of design problems in engineering. It discusses using MATLAB functions like fminbnd, fminsearch, and fminunc for single-variable and multivariable unconstrained optimization. It also discusses using fmincon for constrained optimization and provides examples of optimizing maximum shear stress, column design for minimum mass, and flywheel design for minimum mass. Analytical gradients can be provided to fmincon or it uses numerical gradients via finite differences.
This document discusses optimization techniques for engineering design problems. It provides examples of formulating design optimization problems, including defining design variables, objective functions, and constraints. The examples presented are the design of a two-bar structure to minimize mass and the design of a beer can to minimize material cost while meeting size and volume requirements. The document outlines the standard formulation of optimization problems and considerations for developing the problem definition.
This document discusses machine tool drives. It begins by defining a machine tool as a device that produces geometrical surfaces on solid bodies through firmly holding the tool and work, providing power and motion to the tool and work through drives, and transmitting motion and power through a kinematic system. It notes that machine tools require relative motion between the tool and work, derived from power sources and transmitted through kinematic systems. It also discusses the primary and auxiliary motions of machine tools, with primary motions being either rotating or straight for material removal, and feed movement being either continuous or intermittent.
The document provides an overview of manufacturing, including what manufacturing is, its technological and economic importance, key industries and products, and the main materials used. Manufacturing transforms materials into higher value products through processing and assembly. It is important technologically as it enables society's use of technology, and economically it represents 12% of the US GDP. The main materials used in manufacturing are metals, ceramics, polymers, and composites.
This document discusses various methods of linear measurement in surveying. It describes direct measurement methods like chaining, pacing, and using odometers. It also discusses indirect optical methods like tacheometry and triangulation. Electronic methods involving propagation of light or radio waves are also mentioned. Considerable detail is provided on instruments used for direct measurement, including various types of chains, tapes, pegs, arrows, and rods. The importance of reconnaissance surveys to plan the framework is also highlighted.
This document discusses general concepts of biomedical instrumentation and provides examples of direct and indirect measurement methods. It describes direct measurement using a clinical thermometer and indirect non-contact measurement using an infrared pyrometer. It also discusses direct measurement of intraocular pressure using a Goldmann applanation tonometer and indirect measurement using a non-contact air puff tonometer. Finally, it introduces a new direct measurement technique for intraocular pressure using a rebound tonometer that provides a more patient-friendly alternative.
This document provides an overview of topics related to tolerancing and measurement systems. It discusses reasons for using geometric dimensioning and tolerancing (GD&T), including ensuring interchangeability and maximizing quality. Key concepts covered include tolerance types, tolerance vs manufacturing process, and defining terms like nominal size and tolerance. The document also covers tolerance representation, fits and allowances, geometric tolerances, and tolerance analysis methods like the worst-case method.
This document provides an overview of topics related to tolerancing and measurement systems. It discusses reasons for using geometric dimensioning and tolerancing (GD&T), including ensuring interchangeability and maximizing quality. Key concepts covered include tolerance types, tolerance vs manufacturing process, and defining terms like nominal size and tolerance. The document also covers tolerance representation, fits and allowances, geometric tolerances, and methods for tolerance analysis. The worst-case method is described as establishing dimensions and tolerances such that any combination will produce a functioning assembly.
Metrology is the science of measurement. Dimensional metrology deals with measuring dimensions like lengths and angles of parts. Accurate dimensional measurements are key to ensuring a product matches its design intent. Dimensional metrology involves measuring linear dimensions, angles, geometric forms like roundness and flatness, geometric relationships, surface texture, and more. Geometric Dimensioning and Tolerancing (GDT) uses standard symbols on drawings to specify dimensional requirements.
This document outlines the objectives and content of a course on instrumentation. The course aims to teach students about advances in technology and measurement techniques. It will cover various flow measurement techniques. The course outcomes are listed, along with the cognitive level and linked program outcomes for each. The teaching hours for each unit are provided. The document gives an overview of the course content and blueprint of marks for the semester end examination. It provides details on the units to be covered, including measuring instruments, transducers and strain gauges, measurement of force, torque and pressure, and more.
The document discusses concepts related to measurement and instrumentation systems, including:
1. Measurement involves comparing a physical quantity to a standard unit using an instrument under controlled conditions. Units are needed to give measurements meaning.
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This document provides an overview of MECE 3320 - Measurements and Instrumentation course at the University of Texas - Pan American. It discusses basic concepts of measurement methods, need for measurements, basic quantities and units, derived quantities, general measurement systems, experimental test plans, calibration, accuracy, errors, and strategies for good experimental design. The course introduces concepts like independent and dependent variables, noise and interference, static and dynamic calibration, and discusses illustration of random, systematic errors and accuracy in measurements. It also announces homework 1 and quiz 1 have been posted online.
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New techniques for characterising damage in rock slopes.pdf
Presentation10-9.ppt
1. Pressure, Velocity & Flow
Measurements
ME 310 – Instrumentation
Prof. Jamey D. Jacob
Spring, 2004
2. Overview
• Measurement of Pressure & Velocity
– Related, usually measure pressure to obtain velocity
• Review of Fluid Properties
• Relationship between pressure and velocity
• Pressure variation in the atmosphere and ocean
• Pressure Measurement (Chap. 9)
• Velocity Measurement (Chap. 9)
• Flow Rate Measurement (Chap. 10)
3. Why measure pressure?
• From pressure variation in a moving fluid, one
can obtain velocity
• Measure losses due to friction in ducts and
diffusers
• Use pressure variation to determine
temperature,
density, etc.
• Rate processes in reactions
• Changes in atmospheric conditions
• Safety (max./min. pressure)
4. Measures of Weight
• Specific Weight
– Weight per unit volume
– Units of N/m3 or lb/ft3
• Specific gravity
– Ratio of density of the fluid to water at 4ºC
– Dimensionless
5. Some Numbers of Interest
• The “Common” Fluids
– Air and water (in SI except for ν in cgs) at STP
6. The Continuum Hypothesis
Number of
molecules in
1 cm3 of air =
2.7 ·1019 at STP;
Number of
particles in the
solar wind =
~10-100/cm3
7. Continuum versus Non-continuum Gases
• All liquids can be viewed as a continuum
• Gases at low pressures and densities may be noncontinuum
in nature if the Knudson # is not <<1 - special
devices are required to measure these very low pressures
8. What Causes Motion?
• Balance of forces
– Equilibrium between pressure, viscous, and inertial
forces.
– F=ma ⇒ Navier-Stokes equation
• True for steady and unsteady flows.
– A steady flow reaches an equilibrium, fluid is moving
but flow field does not changes in time.
– An unsteady flow is constantly changing in time.
• Nature abhors a vacuum?
• Nature abhors a pressure gradient!
9. Relation of Pressure to Velocity
• Conservation of momentum (Navier-Stokes)
• Bernoulli’s equation (derived from N-S eq’n)
11. Pressure: gage versus absolute
• Pressure is always positive (negative pressures do
exist, but not in practicality) – can be measured on
an absolute scale or respect to atmospheric
12. Units of Pressure
• Pressure
– Multitudes of units.
– 1 atmosphere is equal to . . . (these are just a few!)
13. Pressure Ranges
• Some typical values of pressure
– Atmospheric
• Hurricane, 700 mm Hg
– Biological
• 120/70 mm Hg ⇒ 1.15 atm to 1.09 atm absolute pressure
(about 2 psi gage)
– Vacuum chambers
• 29 inches Hg (25 mm Hg absolute) to 10-6 Torr (“a lot of
nothingness”)
– ASME Pressure Vessels
• Very small (0 psia) to very big 100 psig to 10,000 psig
14. Atmosphere
• Pressure variation
– Decreases logarithmically
with height, P = 10^(-0.06H,
where P is pressure in
atmospheres and H is
height in km, density
behaves similarly.
• Temperature variation
– Highly complex with
height, due to solar heating
in the troposphere, and
chemical absorption, reradiation
in the
stratosphere, mesosphere,
and thermosphere.
16. What pressure are you measuring?
• Static pressure and dynamic pressure are related
to each other by the stagnation or total pressure
– at equal elevations,
static pressure + dynamic pressure = total pressure
• The total or stagnation pressure is that pressure
that results if the flow is ideally brought to rest
(stagnated)
18. Pressure Measuring Devices
• Basic pressure measuring devices fall into two
basic categories
– Liquid-Column Manometers: pressure is measured
by
using hydrostatic behavior of a column of liquid
– Electro-Mechanical Transducers: pressure is
measured
by (essentially) direct measurement of force or
deflection due to pressure on a given area
• It is common to find multiple devices in a system,
particularly when different magnitudes of
pressure are being measured
19. Device Breakdown
• A more rigorous categorization reveals the
following
– Gravitational devices
• Liquid columns
• Pneumatic or hydraulic pistons
– Direct-acting elastic
• Loaded tubes, symmetric or asymmetric
• Elastic diaphragms
• Bellows devices
– Other devices
20. Direct versus Differential
• A pressure measuring device (manometer or
transducer) can measure pressure of a single
input or the difference between two pressure
inputs
• Differential is useful when measuring fluid
velocity or losses in a duct, for example
21. The Liquid Column Manometer
• The basis of the liquid column manometer is the
hydrostatic pressure relation
which can be integrated to
obtain
showing the pressure variation from one height
to another in a liquid column density ρ
• Pressure is a function of density and height alone
22. The Piezometer Tube
• Uses a single tube to relate height of liquid
column to pressure of a liquid in a pipe or vessel
– Accurate, but requires high
columns
of liquid for large pressures (for a
pressure of 14.7 psig, a column of
water must be 34 feet!)
– Can be used with liquids only
– Cannot measure vacuum pressure
(air is sucked into the liquid)
23. The Inclined Piezometer Tube
• Since pressure is a function of height only, the
tube can be inclined to increase accuracy
Greater accuracy can be attained
by decreasing the value of the
inclination angle since
– For example, if θ =10o
24. Well Manometer
• Useful for barometric pressure measurements
(pressure variation due to atmospheric pressure)
– Pressure in closed tube can be
known at time of construction so
– or air in closed tube can
withdrawn so that it is nearly
vacuum (p=0), thus
25. U-tube Manometer
• Most common type of liquid column manometer
– Measures pressure difference
between two inputs
– Inputs can be both static, both
total, or a mix
– Can be inclined as well to achieve
better accuracy
– Can use two different fluids to
obtain greater accuracy
27. Example
• Take a U-tube manometer that using water that
has a height difference of 1 inch. What is p?
• This difference in pressures is approximately
0.2% above atmospheric pressure - i.e., a very
small change.
31. Dead Weight Tester
• Balances a fluid pressure against a known weight
• Used for pressure gage calibration
32. Pressure ⇒ Displacement
• Consider the spring system
• Now use this relation to determine pressure
• This is a Bellows gage
33. Bourdon Tube Gage
• Most common gage – widely used in all field from
engineering to medical
• Gages available over pressure ranges of <1 to
>106 mm Hg (.001 atm to 1000 atm)
34. Diaphragm Gages
• Uses the deflection of a diaphragm to measure
pressure – the greater the pressure applied on
the diaphragm, the larger the deflection
• Can be flat or corrugated
Top
Side
From omega.com
35. Strain-Gage Based Transducer
• Strain-gage placed on diaphragm
• Can be used for small spans and differential
pressures
From omega.com
36. Capacitance Transducer
• Deflection in diaphragm
registers a change in
capacitance that is picked
up by a bridge circuit
• Can be used from high
vacuums (<< 1 Torr) to 70
MPa (10,000 psig)
37. Pontentiometric Transducer
• Bourdon or Bellows tube connected to a wiper
arm that changes variable resistor in a
Wheatstone Bridge circuit
• Ranges from 35 kPa to 70 MPa (5 to 10,000 psig)
42. Gage Connections
• Since transducers require
periodic calibration and
replacement, the gage is
placed in a test circuit is
shown
• Process pressure is
measured by opening valve P
while D is used to drain the
fluid from the sensor; T is
used for calibration
• Other items, such as
condensors, filters and
snubbers may also be needed
43. Transient Response
• Fluctuations in pressure common in many
systems (take the human body for example; or
the pressure in a internal combustion engine)
• Thus, transient response is important
• The mass of fluid in a sensor vibrates under the
influence of fluid friction which tends to dampen
the oscillatory motion
Sensor
44. Transient Response
• Since the tube is small, assume the flow is laminar; the
resulting expression for pressure-amplitude ratio is
• Where f is the frequency of the pressure signal. The natural
frequency fn is
• While the damping ratio is
• Where L is the tube length, r is the tube radius, V is the
sensor volume, and c the speed of sound
45. Transient Response Example
• A tube with d=0.5 mm diameter and L=7.5 cm
length is connected to a pressure transducer with
a volume V=3.5 cm3; air at STP is the working
fluid – how much does 100 Hz signal attenuate?
46. Transient Response Example
• For the given conditions, the pressure
attenuates
as a function of the input signal
frequency as
shown below
p/po
48. Flow Rate versus Velocity
• Flow rate is an integral quantity
– Flux of flow through a given area
• Velocity is a differential quantity
– Velocity of flow at a given point
• Velocity over an area can be used to
obtain flow
rate; flow rate can be used to determine an
average velocity only
49. Flow Rate
• Integral quantity
• Measures total flow rate in a duct or
enclosure;
no account for variation in local flow rate
• Volumetric flow rate: [L3/t]
– US: ft3/s, GPM (gallons/min), CFM (cubic
feet/min)
– SI: m3/s
• Mass flow rate: [M/t]
– US: lbm/s, slug/s
– SI: kg/s
51. Velocity
• Velocity is a differential quantity;
function of
space (and possibly time)
• Thus, any measure of velocity is a point
measurement; i.e., only the value of velocity at
that measurement location is known
€ • Continuity equation in differential form is
52. Relation between Q (or dm/dt) and V
• Volumetric flow rate, Q, and mass flow rate,
dm/dt, can be related to velocity by continuity
• Only average velocity can be obtained if flow rate
is known
53. U versus Q
• Average velocity may or may not be close to
maximum velocity; highly Re dependent
55. Flow through a Constriction
• In incompressible lossless flow through a
constriction, mass conservation dictates that the
velocity must increase while Bernoulli’s equation
predicts a subsequent pressure drop
56. Obstruction Meters
• This effects leads to the development and use of
obstruction meters; the flow is restricted and the
resulting pressure drop can be used to determine
flow rate in a pipe
• Type of obstruction meter depends on geometry
of restriction
– Venturi: smooth restriction
– Orifice plate: plate with hole (sudden contraction
and
expansion)
– Nozzle: plate with nozzle (gradual contraction,
sudden
expansion)
57. Venturi meter
• Tube installed into pipeline
• Pressure drop from 1 to 2 determines flow rate
from theory (Bernoulli) with corrections for
losses (K)
• Pressure drop varies as square of flow rate;
requires sensitive gage
58. Orifice plate
• Similar in concept to venturi meter, but simpler to
manufacture
• Simpler geometry increases flow losses and
accuracy
• Vena contracta determines discharge coefficient
60. Problem 10.6
• Find the discharge coefficient for a 5 cm diameter
square edged orifice plate using flange taps in a
15 cm pipe if Re=250,000.
• From Figure 10.6, K=0.6=CE
61. Variable-area meters
• Also called rotameters;
flow is diverted in a
tube of variable area
with a float
• Buoyancy and weight
of the float are
balanced by pressure
and viscous fluid
forces
• Linear with flow rate
62. Turbine Meter
• Rate of rotor spin
related to flow rate
• Counter devices
measures RPMs
63. Vortex Shedding Meters
• Vortex shedding frequency can be nondimensionalized
and shown to be constant for a
given geometry over a range of Re
• Thus, flow rate (average velocity) can be
determined by measuring shedding frequency
64. Electromagnetic
• Operates off of Faraday’s law; a voltage is
induced when a conductor (the liquid) moves
through a magnetic field
• Voltage is proportional to flow rate
• Measures forward and reverse flow
65. Ultrasonic
• Doppler type and time-of-travel meters
• Doppler uses a single trasmitter and
measures
the time it takes for a signal to bounce off;
Doppler shift is related to the flow
velocity
• Time of travel meters use two elements
66. Vibrating Flow Meters
• Also called Coriolis meters
• Deflection in a u-tube is directly
related to flow
rate due to Coriolis forces from turning
fluid
69. U-tube Manometer
• Most common type of liquid column manometer
• Can be used to obtain velocity
by using static and stagnation
pressure as the inputs
• Usually denoted on manometers
by high and low pressure inputs
(stagnation and static,
respectively)
70. The Liquid Column Manometer
• When using a liquid column manometer,
combine
the hydrostatic equation with Bernoulli’s
equation
71. The Inclined Manometer
• Since pressure is a function of height only, the
tube can be inclined to increase accuracy
72. Problem 9.5
• An inclined manometer measures 5.6 cm H20 with
an inclination of 30o; what is the actual pressure
change?
73. Pitot-Static Tube
• Accurate to within 15-20o of
orientation with
respect to free-stream
• Measures velocity magnitude
only; not direction
74. Turbometer
• Same principle as turbine-meters, except
turbine
rotation is correlated with velocity not flow rate
76. Hot-Wire Anemometry
• Consider a thin wire mounted to supports and exposed to a
velocity U. When a current is passed through wire, heat is
generated (I2Rw). In equilibrium, this must be balanced by
heat loss (primarily convective) to the surroundings.
If velocity changes,
convective heat
transfer coefficient
will change, wire
temperature will
change and
eventually reach a
new equilibrium.
78. Laser-Doppler Velocimetry
• LDV
– Focused laser beams intersect and form the
measurement
volume
– Plane wave fronts: beam waist in the plane
of intersection
– Interference in the plane of intersection
– Pattern of bright and dark stripes/planes
81. PIV
• Particle Image Velocimetry
– Field technique – measures 2D (u and v) velocity in a
plane instantaneously
– Essentially tracks seeded flow from one digital
image to
another