pressure transducers

Production Engineering Department

Faculty of Engineering

Alexandria University

Types of Pressure Transducers

Prepared for

Fluid Mechanics Staff,

Mechanical Engineering Department

Under supervision of

Dr. Ahmed Bahaa

Prepared by

A. Marmaras, Z. Mohamed, O. Tarek, M. Ashraf, H. Salah

TYPES OF PRESSURE TRANSDUCERS

i

Table of Contents

Measuring system components ................................................................................................. 1

Basic requirements of a transducer ........................................................................................... 1

Transducers in our daily life ....................................................................................................... 2

Transducers in various applications ........................................................................................... 2

Industry .................................................................................................................................. 2

Environment........................................................................................................................... 2

Safety and Security ................................................................................................................ 3

Classroom ............................................................................................................................... 3

Types of transducers .................................................................................................................. 3

Mechanical displacement transducers ...................................................................................... 3

Temperature transduces ........................................................................................................... 3

Pressure transducers ................................................................................................................. 3

Types of pressure transducers ............................................................................................... 3

How it works .......................................................................................................................... 4

Electric pressure transducers ..................................................................................................... 5

Working principle ................................................................................................................... 5

Main components of electrical pressure transducer............................................................. 5

Common types of electric pressure transducers ................................................................... 5

Capacitive pressure transducer ................................................................................................. 5

Working principle of capacitive pressure transducers .......................................................... 6

Advantages of capacitive pressure transducers .................................................................... 6

Disadvantages of capacitive pressure transducers................................................................ 6

Strain gauge pressure transducer .............................................................................................. 6

Construction of strain gauge pressure transducer ................................................................ 6

Working principle of strain gauge pressure transducer ........................................................ 7

Measurement Circuits of strain gauge pressure transducer ................................................. 7

Advantages of a strain gauge pressure transducer ............................................................... 8

Disadvantages of a strain gauge pressure transducer ........................................................... 8

Potentiometer pressure transducer .......................................................................................... 8

Working principle of Potentiometer pressure transducer .................................................... 8

Advantages of Potentiometer pressure transducer .............................................................. 8

Disadvantages of Potentiometer pressure transducer.......................................................... 8

Electromagnetic pressure transducer ........................................................................................ 9

Types of electromagnetic pressure transducer ..................................................................... 9


ii

Working principle of electromagnetic pressure transducer .................................................. 9

Advantages of electromagnetic pressure transducer ........................................................... 9

Disadvantages of electromagnetic pressure transducer ....................................................... 9

Piezoelectric pressure transducer ............................................................................................. 9

What is Piezoelectricity? ........................................................................................................ 9

Working principle of piezoelectric pressure transducer ....................................................... 9

Common types of piezoelectric pressure transducers ........................................................ 10

Charge mode type ............................................................................................................ 10

Low impedance voltage mode type ................................................................................. 10

Advantages of Piezoelectric pressure transducer ............................................................... 10

Disadvantages of Piezoelectric pressure transducer ........................................................... 10

Elastic pressure transducers .................................................................................................... 11

Common types of elastic pressure transducers .................................................................. 11

Bourdon tube pressure transducer ......................................................................................... 11

Working Principle of bourdon tube pressure transducer .................................................... 11

Advantages of bourdon tube pressure transducer ............................................................. 12

Disadvantages of bourdon tube pressure transducer ......................................................... 12

Applications of bourdon tube pressure transducer ............................................................ 12

Diaphragm pressure transducer .............................................................................................. 12

Working principle of diaphragm pressure transducer ......................................................... 12

Types of diaphragm pressure transducer ............................................................................ 13

Metallic diaphragms ........................................................................................................ 13

Slack diaphragms ............................................................................................................. 13

Advantages of diaphragm pressure transducer .................................................................. 13

Disadvantages of diaphragm pressure transducer .............................................................. 13

Applications of diaphragm pressure transducer ................................................................. 13

Bellows pressure transducer ................................................................................................... 14

Working principle of bellows pressure transducer .............................................................. 14

Advantages of bellows pressure transducer ....................................................................... 14

Disadvantages of bellows pressure transducer ................................................................... 14

Applications of bellows pressure transducer ...................................................................... 14

Limitations and challenges....................................................................................................... 15

References ............................................................................................................................... 16

Team members ........................................................................................................................ 17


iii

List of Figures

Figure 1: Fundamental elements of a measuring instrument ................................................... 1 Figure 2: Block diagrams for pressure transducers ................................................................... 4 Figure 3: Capacitive pressure transducer .................................................................................. 5 Figure 4: Working principle of capacitive pressure transducer ................................................. 6 Figure 5: Strain gauge pressure transducer ............................................................................... 6 Figure 6: Construction and working principle of a strain gauge pressure transducer .............. 7 Figure 7: Different measurement circuits of strain gauge pressure transducer ....................... 7 Figure 8: Potentiometer pressure transducer ........................................................................... 8 Figure 9: Electromagnetic pressure transducer ......................................................................... 9 Figure 10: Piezoelectric pressure transducer ............................................................................ 9 Figure 11: Symbolic presentation of charge mode type measuring station ........................... 10 Figure 12: Symbolic presentation of LIVM mode type measuring station .............................. 10 Figure 13: Bourdon tube pressure transducer ........................................................................ 11 Figure 14: Working principle of bourdon tube pressure transducer....................................... 11 Figure 15: Diaphragm pressure transducer ............................................................................. 12 Figure 16: Metallic diaphragm pressure transducer ............................................................... 13 Figure 17: Slack diaphragm pressure transducer .................................................................... 13 Figure 18: Bellows pressure transducer .................................................................................. 14

List of Tables

Table 1: Transducers in our daily life ......................................................................................... 2


INTRODUCTION

1

Measuring system components

Sensor

A device that converts a physical parameter to an electrical output. It receives and responds to a signal or stimulus.

Actuator

A device that converts a physical parameter to an electrical output.

Transducer

A device that converts one type of energy to another. Energy forms can be mechanical, visual, aural, electrical, thermal, chemical, etc. Also, it is used to change information into a form that can be easily transferred, stored, processed, interpreted, etc.

A complete knowledge of its electrical and mechanical characteristics is of great importance while choosing it for a particular application.

Figure 1: Fundamental elements of a measuring instrument

Basic requirements of a transducer

Ruggedness

Ability to withstand over loads with safety stops for over load Protection.

Linearity

Ability to reproduce input-output characteristics symmetrically and linearly and it is the main factor considered.

Repeatability

Ability to reproduce the output signal exactly when the same measurand is applied repeatedly under the same environmental conditions.


INTRODUCTION

2

Convenient instrumentation

Sufficiently high analog output signal with high signal to noise ratio. Digital output preferred in many cases.

High stability and reliability

Minimum error in measurement. Effect of temperature, vibrations and environmental variations are not considered.

Good dynamic response

Output is faithful to input when taken as a function of time. It is analyzed as the frequency response.

Additional requirements

Excellent mechanical characteristics and Built in integrated device with noise, asymmetry and other defects minimized.

Transducers in our daily life

Table 1: Transducers in our daily life

Type Input Output Examples

Electromagnetic Electromagnetic

field Current

Receiving/transmitting antennas

Electromechanical Substance Voltage PH probe/fuel cell

Electromechanical Movement Voltage Motor /phonograph

cartridge

Electroacoustic Vibration Voltage Loudspeaker/microphone

Photoelectric Light Voltage Light bulb/photodiode

Thermoelectric Temperature Voltage Hotplate/thermistor

Transducers in various applications

Industry

On the factory floor, networked vibration sensors warn that a bearing is beginning to fail. Mechanics schedule overnight maintenance, preventing an expensive unplanned shutdown. Inside a refrigerated grocery truck, temperature and humidity sensors monitor individual containers, reducing spoilage in fragile fish or produce.

Environment

Networks of wireless humidity sensors monitor fire danger in remote forests. Nitrate sensors detect industrial and agricultural runoff in rivers, streams and wells, while distributed seismic monitors provide an early warning system for earthquakes. Meanwhile built-in stress sensors report on the structural integrity of bridges, buildings and roadways, and other man-made structures.


INTRODUCTION

3

Safety and Security

Firefighters scatter wireless sensors throughout a burning building to map hot spots and flare-ups. Simultaneously, the sensors provide an emergency communications network. Miniature chemical and biological sensors in hospitals, post offices, and transportation centers raise an alarm at the first sign of anthrax, smallpox or other terror agents.

Classroom

Sensor technology provides teachers with an exciting alternative to the time consuming task of manually logging and observing science experiments. Instead of using stopwatches, thermometers and barometers, students are using sensors and powerful software to collect and analyze data as they are carrying out their experiments. This provides more accurate readings than the old manual methods and data is collected in a more exciting way.

Types of transducers

Mechanical displacement transducers.

Temperature transduces (using mechanical/electrical properties to operate).

Level transducers.

Flow transducers (direct/indirect).

Pressure transducers (static/dynamic).

Mechanical displacement transducers

Displacement sensors are widely used not only to measure the distance of a moving object but also it can be embedded in other sensors or transducer devices to measure pressure or level or flow as it will be shown later. Many physical variables have the capability to produce a displacement that can be converted into active signal. This is the basic principle in many transducer devices.

Temperature transduces

Temperature transducers are used extensively in process industries such as chemical, food and pharmaceuticals, where control of temperature during manufacturing is important. Three commonly used temperature transducers are the thermocouple, the resistance temperature detector (RTD) and the thermistor.

Pressure transducers

Types of pressure transducers

Electric pressure transducers.

Elastic, also called mechanical, pressure transducers.


INTRODUCTION

4

How it works

Figure 2: Block diagrams for pressure transducers


ELECTRIC PRESSURE TRANSDUCERS

5

Electric pressure transducers

Working principle

The mechanical loading produces a change of length in the measurement object, which is conveyed to the strain gauge. As there is a change in length, the electrical resistance of the applied strain gauge also changes in proportion to the strain. If there is excitation voltage, the circuit supplies an output signal proportional to the change in resistance and therefore also proportional to the change in length. A carrier frequency or DC amplifier suitable for strain gauges enables measurement signal evaluation to continue.

Main components of electrical pressure transducer

Pressure sensing.

Primary conversion element.

Secondary conversion element.

Common types of electric pressure transducers

Capacitive pressure transducers.

Strain gauge pressure transducers.

Potentiometer pressure transducers.

Electromagnetic pressure transducers.

Piezoelectric pressure transducers.

Capacitive pressure transducer

Capacitive pressure transducers are expertly designed adaptations of a simple, durable and fundamentally stable device which is the electrical capacitor. Like the parallel plate electrical capacitor, it uses a diaphragm and pressure cavity to create a variable capacitor to detect strain due to applied pressure. The diaphragm, commonly, is ceramic, and silicon. The firmly secured surfaces are mounted so that a slight mechanical flexing of the assembly, caused by a minute change in applied pressure, alters the gap between them creating a variable capacitor. The resulting change in capacitance is detected by a sensitive linear comparator circuit which amplifies and outputs a proportional, high-level signal.

Figure 3: Capacitive pressure transducer



6

Working principle of capacitive pressure transducers

The electrical capacitor has two metal plates and a dielectric material sandwiched between them. In capacitive pressure transducer, one of these metal plates is permitted to move in and out so that the capacitance between them changes due to varying distance between the plates. The movable plate is connected to a diaphragm which senses the pressure and then expands or compresses accordingly. The movement of the diaphragm would affect the attached metal plates position and capacitance would vary.

Advantages of capacitive pressure transducers

High input impedance and require small force for operation.

Having good frequency response and less affected by stray magnetic fields.

Measuring low pressures.

Disadvantages of capacitive pressure transducers

Guard rings are necessaries so as to minimize stray electric fields

Complex circuit arrangement like bridge circuit.

The performance may be affected by parameters like dust, temperature.

Strain gauge pressure transducer

Strain gauge is passive type of resistance pressure transducer, whose electrical resistance changes when it is stretched or compressed. It can be used as a secondary element in pressure measurement. It can be attached to bellows and diaphragms to effectively measure pressure. Usually, it contains a silicon chip with an integral sensing diaphragm and four strain gauges.

Construction of strain gauge pressure transducer

Simply, the strain gauge is a fine wire which changes its resistance when mechanically strained, due to physical effects. The most common type of strain gauge is attached to the diaphragm.

Figure 5: Strain gauge pressure transducer

Figure 4: Working principle of capacitive pressure transducer



7

Working principle of strain gauge pressure transducer

When the diaphragm flexes due to the process pressure applied on it, the strain gauge stretches or compresses. This deformation of the strain gauge causes the dissimilarity in its length and cross sectional area due to which its resistance also changes. This change is usually converted into voltage by linking one, two, or four similar gauges as of Wheatstone bridge to maximize the output of the sensor and to reduce sensitivity to errors. Usually, one arm of the wheat stone bridge is connected to a diaphragm which compresses and expands due to the pressure applied. This variation causes the output in the bridge to vary. The bridge output voltage is then a measure of the pressure sensed by strain gauges.

Measurement Circuits of strain gauge pressure transducer

Common Wheatstone bridge circuit and all resistances are equal but one is variable by a factor (1+x), where x is a fractional deviation around zero, as a function of strain. Sufficiently linear for small values of x. Op amp forces the bridge to be balanced. It has good linearity and very low output impedance, thus making the output measurement easier and more accurate.

Figure 7: Different measurement circuits of strain gauge pressure transducer

Figure 6: Construction and working principle of a strain gauge pressure transducer



8

Advantages of a strain gauge pressure transducer

Small, easy to install and simple to maintain.

Good accuracy and stability.

High output signal strength, over range capacity.

No moving parts.

Fast speed of response.

Availability for wide range of measurements.

Good shock and vibration characteristics.

Disadvantages of a strain gauge pressure transducer

Requiring temperature compensation and constant voltage supply.

Moderate to high cost.

Electrical readout is necessary.

Potentiometer pressure transducer

The potentiometer which is made by winding resistance wire around an insulated cylinder. A moveable electrical contact, called a wiper, slides along the cylinder, touching the wire at one point on each turn. A mechanical linkage from the pressure sensing element controls the position of the wiper on the potentiometer.

Working principle of Potentiometer pressure transducer

It uses the motion of a wiper along a resistive mechanism to detect the strain caused by applied pressure. The position of wiper determines the resistance of the potentiometer which in turn determines the pressure. An increase in pressure makes the bourdon tube straighten out partially. This motion causes the linkage to move the wiper across the winding on potentiometer as the wiper moves, the resistances between terminals A and B which is equal to the pressure sensed by the bourdon tube.

Advantages of Potentiometer pressure transducer

Strong output and no need of additional amplifier.

High range, ruggedness and electrical efficiency.

Low cost.

Disadvantages of Potentiometer pressure transducer

Finite resolution, limited life and large size.

Poor frequency to response and tendency to develop noise.

Figure 8: Potentiometer pressure transducer



9

Electromagnetic pressure transducer

Types of electromagnetic pressure transducer

Linear variable differential transformer.

Servo pressure transducers.

Working principle of electromagnetic pressure transducer

Measures the displacement of a diaphragm by means of changes in inductance.

Advantages of electromagnetic pressure transducer

High sensitivity, ruggedness and stability.

Infinite resolution.

Low hysteresis.

High degree of shock and vibration.

Disadvantages of electromagnetic pressure transducer

Sensitivity to stray magnetic fields but shielding is possible.

Temperature effects the performance of transducers.

Piezoelectric pressure transducer

What is Piezoelectricity?

The word is derived from the Greek word piezien, which means to squeeze or press. Piezoelectricity is the ability of some materials, notably crystals and certain ceramics, to generate an electrical potential in response to applied mechanical stress. This may take the form of a separation of electric charge across the crystal lattice. If the material is not short circuited, the applied charge induces a voltage across the material.

Working principle of piezoelectric pressure transducer

It uses the piezoelectric effect in certain materials such as quartz to generate rapid electrical signals and measuring the strain upon the sensing mechanism due to pressure.

Figure 9: Electromagnetic pressure transducer

Figure 10: Piezoelectric pressure transducer



10

Common types of piezoelectric pressure transducers

Charge mode type

It is manufactured with both ceramic and crystalline quartz piezoelectric elements. Charge mode accelerometers used for vibration measurements utilize piezo-ceramic materials from the lead zirconium titanate family. These materials are characterized by high charge output, high internal capacitance, relatively low insulation resistance and good stability.

Low impedance voltage mode type

It is available for pressure and force measurements as well. The LIVM accelerometer uses crystalline quartz as the signal generating element instead of piezo-ceramic. Unlike the charge mode accelerometer, the LIVM accelerometer utilizes the voltage signal generated by the quartz element rather than the charge signal.

A miniature IC metal oxide silicon field effect transistor amplifier is built into the housing to convert the high impedance voltage signal from the quartz element to a much lower output impedance level, so the readout instrument and long cable have little effect on the signal quality. Because of the high impedance input, the LIVM sensor is relatively impervious to external electrostatic interference and other disturbances.

Unlike the charge mode type, it requires current source power unit. The power unit contains a DC power source and a means of blocking or otherwise eliminating the DC bias voltage that exists at the center terminal of the sensor connector, so the signal may be conveniently coupled to the readout instrument.

Advantages of Piezoelectric pressure transducer

No need for external power.

It has a good frequency response.

Disadvantages of Piezoelectric pressure transducer

Cannot measure static pressure.

Output affected by changes in temperature.

Figure 11: Symbolic presentation of charge mode type measuring station

Figure 12: Symbolic presentation of LIVM mode type measuring station


ELASTIC PRESSURE TRANSDUCERS

11

Elastic pressure transducers

The elastic pressure transducers are the mechanical elements that are used for converting one form of energy into the other form of energy that can be measured easily.

Common types of elastic pressure transducers

Bourdon tube pressure transducers.

Diaphragm pressure transducers.

Bellows pressure transducers.

Bourdon tube pressure transducer

The basic idea behind the device is that, cross-sectional tubing when deformed in any way will tend to regain its circular form under the action of pressure. The bourdon pressure gauges used today have a slight elliptical cross-section and the tube is generally bent into a C-shape or arc length of about 27 degrees. Bourdon Tubes are known for its very high range of differential pressure measurement.

Working Principle of bourdon tube pressure transducer

The pressure input is given to a socket which is soldered to the tube at the base. The other end or free end of the device is sealed by a tip connected to a segmental lever through an adjustable length link. The segmental lever is suitably pivoted and the spindle holds the pointer. A hair spring is sometimes used to fasten the spindle of the frame of the instrument to provide necessary tension for proper meshing of the gear teeth and thereby freeing the system from the backlash. Any error due to friction in the spindle bearings is known as lost motion. The mechanical construction has to be highly accurate in the case of a Bourdon Tube Gauge. If we consider a cross-section of the tube, its outer edge will have a larger surface than the inner portion. The tube walls will have a thickness between 0.01 and 0.05 inches.

Bourdon gauges can also be constructed in the form of a helix or a spiral for better linearity and larger sensitivity. For thorough repeatability, the bourdon tubes materials must have good elastic or spring characteristics. The surrounding in which the process is carried out is also important as corrosive atmosphere or fluid would require a material which is corrosion proof. The commonly used materials are phosphor-bronze, silicon-bronze, beryllium-copper and other C-Cr-Ni-Mo alloys.

Figure 13: Bourdon tube pressure transducer

Figure 14: Working principle of bourdon tube pressure transducer



12

Advantages of bourdon tube pressure transducer

Low cost and simple construction.

Time-tested in applications.

Availability in a wide variety of ranges.

Adaptability to transducer designs for electronic instruments.

High accuracy, especially in relation to cost.

Disadvantages of bourdon tube pressure transducer

Low spring gradient.

Susceptibility to hysteresis, shock and vibrations.

Applications of bourdon tube pressure transducer

Pressure monitoring and direct switching of electrical loads.

Gaseous and liquid, aggressive, highly viscous media and aggressive ambience.

Process industry: chemical/petro-chemical, on- and offshore, technical gases, environmental technology, machine building and general plant construction, water treatment, pharmaceutical industry.

Diaphragm pressure transducer

A diaphragm pressure transducer is used for low pressure measurement. They are commercially available in two types.

Working principle of diaphragm pressure transducer

When a force acts against a thin stretched diaphragm, it causes a deflection of the diaphragm with its center deflecting the most. Since the elastic limit has to be maintained, the deflection of the diaphragm must be kept in a restricted manner. This can be done by cascading many diaphragm capsules. A main capsule is designed by joining two diaphragms at the periphery. A pressure inlet line is provided at the central position. When the pressure enters the capsule, the deflection will be the sum of deflections of all the individual capsules. Corrugated diaphragms are also used instead of the conventional ones.

Corrugated designs help in providing a linear deflection and also increase the member strength. The total amount of deflection for a given pressure differential is known by some factors, number and depth of corrugation and capsules, capsule diameter, shell thickness and material characteristics.

Figure 15: Diaphragm pressure transducer



13

Types of diaphragm pressure transducer

Metallic diaphragms

Known to have good spring characteristics. Used materials are the same as those used for Bourdon Tube.

Slack diaphragms

Known to have non-elastic characteristics and used rarely. Due to their non-elastic characteristics, the device will have to be opposed with external springs for calibration and precise operation. They are used for measuring very small pressures. The commonly used materials for making the diaphragm are polythene, neoprene, animal membrane, silk, and synthetic materials.

Advantages of diaphragm pressure transducer

Moderate cost and small size.

Diaphragm Pressure Transducer possesses high over range characteristics.

Adaptable to absolute and differential pressure measurement.

Having a good linearity.

Disadvantages of diaphragm pressure transducer

Lack of good vibration and shock resistance.

Difficult to repair.

Limited to relatively low pressures.

Applications of diaphragm pressure transducer

The best example for a slack diaphragm is the draft gauge. They are used in boilers for indication of the boiler draft. The device can control both combustion and flue. With the draft, usually of pressure less than the atmosphere, connected, the power diaphragm moves to the left and its motion is transmitted through the sealing diaphragm, sealed link and pointer drive to the pointer

Process industry: Biotechnology and pharmaceutical industries, cosmetics manufacturing, food industry

Quick cleaning of measuring point, without residue

For gaseous and liquid aggressive media that are highly viscous or crystallizing, also in aggressive ambience.

Figure 16: Metallic diaphragm pressure transducer

Figure 17: Slack diaphragm pressure transducer



14

Bellows pressure transducer

Like a diaphragm, bellows are also used for pressure measurement, and can be made of cascaded capsules. The basic way of manufacturing bellows is by fastening together many individual diaphragms. The bellows element, basically, is a one piece expansible, collapsible and axially flexible member. It has many convolutions or fold. It can be manufactured form a single piece of thin metal. For industrial purposes, the commonly used bellow elements are:

By turning from a solid stock of metal

By soldering or welding stamped annular rings

Rolling a tube

By hydraulically forming a drawn tubing

Working principle of bellows pressure transducer

The action of bending and tension operates the elastic members. For proper working, the tension should be least. The design ideas given for a diaphragm is applied to bowels as well. The manufacturer describes the bellows with two characters, maximum stroke and maximum allowable pressure. The force obtained can be increased by increasing the diameter. The stroke length can be increased by increasing the folds or convolutions.

Some the parameters to has be checked for selecting a specific material for an elastic member like bellows, range of pressure, hysteresis, fatigue on dynamic operation, corrosion, fabrication ease and sensitivity to fluctuating pressures.

Advantages of bellows pressure transducer

Moderate cost.

Delivery of high force.

Adaptability for absolute and differential pressure.

Good in the low to moderate pressure range.

Disadvantages of bellows pressure transducer

Ambient temperature compensation needed.

Unsuitable for high pressure.

Limited availability of metals and work hardening of some of them.

Unsuitability of its zero and the stiffness, therefore it is used in conjunction with a reliable spring of appreciably higher stiffness for accurate characterization.

Applications of bellows pressure transducer

Gas Filled bellows can make the sensor sensitive to both external pressure and temperature in vastly different applications.

Liquid Filled bellows can function in a number of transducer applications.

Figure 18: Bellows pressure transducer


LIMITATIONS AND CHALLENGES

15

Limitations and challenges

Pressure sensors have several limitations that restrict their use in several areas. High temperature dependency, hysteresis, inability to deduce quick and dynamic pressure variations, sensitivity to the external vibrations, irreparability of the electronic board assembly, sensitivity to electric, magnetic and RF fields, incompatibilities with external devices are few challenges that a general pressure sensor faces. In some applications, pressure sensors have limited accuracy. For example, in a touch screen, the sensitivity of the sensor when multiple touches are made is affected while in the aviation sector high pressure can limit the working of the sensor.

Pressure sensors are essentially required to make a device respond to its ambient conditions in an optimized manner. Their types and uses are plenty and will continue to evolve as the sensor technology continues to mature. Extensive use of pressure sensors such as in touch screens or automobiles degrades their efficiency quite soon and hence the ruggedness of the pressure sensors is also a growing priority of industrial research. Nevertheless, pressure sensors tools, and as it goes with every other tool, these are to be used carefully as well as checked constantly to ensure quality results.


16

References

1. W. Tompkins, , J. Webster. Interfacing Sensors To The IBM PC. . s.l. : Prentice Hall Inc., 1988.

2. Singh, S k. Industrial Instrumentation and Control. New DEHLI : Tata McGraw HILL company Limited, 1987.

3. Patranabis, D. Sensors and Transducers.

4. Pallas-Areny. Sensors and Signal Conditioning. s.l. : Wiley, 1991.

5. Gautschi, G. Piezoelectric sensorics. New York : Springer Berlin, 2002.

6. Dally, Riley, and McConnell. Instrumentation for Engineering Measurements. s.l. : Wiley, 1993. 2nd Ed.

7. Carstens. Electrical Sensors and Transucers. s.l. : Prentice Hall, 1993.


17

Team members

Name Section Number Seat Number

Alexia Constantin Marmaras 2 42

Ziad Mohamed El-Sayed 3 79

Ola Tarek Ali 4 101

Mahmoud Ashraf Mohamed 7 176

Hadeer Salah Kamel 8 217

Measuring system componentsSensorActuatorTransducer

Basic requirements of a transducerRuggednessLinearityRepeatabilityConvenient instrumentationHigh stability and reliabilityGood dynamic responseAdditional requirements

Transducers in our daily lifeTransducers in various applicationsIndustryEnvironmentSafety and SecurityClassroom

Types of transducersMechanical displacement transducersTemperature transducesPressure transducersTypes of pressure transducersHow it works

Electric pressure transducersWorking principleMain components of electrical pressure transducerCommon types of electric pressure transducers

Capacitive pressure transducerWorking principle of capacitive pressure transducersAdvantages of capacitive pressure transducersDisadvantages of capacitive pressure transducers

Strain gauge pressure transducerConstruction of strain gauge pressure transducerWorking principle of strain gauge pressure transducerMeasurement Circuits of strain gauge pressure transducerAdvantages of a strain gauge pressure transducerDisadvantages of a strain gauge pressure transducer

Potentiometer pressure transducerWorking principle of Potentiometer pressure transducerAdvantages of Potentiometer pressure transducerDisadvantages of Potentiometer pressure transducer

Electromagnetic pressure transducerTypes of electromagnetic pressure transducerWorking principle of electromagnetic pressure transducerAdvantages of electromagnetic pressure transducerDisadvantages of electromagnetic pressure transducer

Piezoelectric pressure transducerWhat is Piezoelectricity?Working principle of piezoelectric pressure transducerCommon types of piezoelectric pressure transducersCharge mode typeLow impedance voltage mode type

Advantages of Piezoelectric pressure transducerDisadvantages of Piezoelectric pressure transducer

Elastic pressure transducersCommon types of elastic pressure transducers

Bourdon tube pressure transducerWorking Principle of bourdon tube pressure transducerAdvantages of bourdon tube pressure transducerDisadvantages of bourdon tube pressure transducerApplications of bourdon tube pressure transducer

Diaphragm pressure transducerWorking principle of diaphragm pressure transducerTypes of diaphragm pressure transducerMetallic diaphragmsSlack diaphragms

Advantages of diaphragm pressure transducerDisadvantages of diaphragm pressure transducerApplications of diaphragm pressure transducer

Bellows pressure transducerWorking principle of bellows pressure transducerAdvantages of bellows pressure transducerDisadvantages of bellows pressure transducerApplications of bellows pressure transducer

Limitations and challengesReferencesTeam members

pressure transducers

Documents