LINEAR POTENTIOMETER Potentiometers are electrical devices which are a form of variable resistance.
It consists of a sliding contact which moves over the length of a resistance element. This sliding contact connects to a plunger, which links to the object whose displacement is to be measured.
Referring to the electrical circuit shown here, An input voltage Xt is applied across the whole resistance element, at points A and C. The output voltage, Xi , is measured between the sliding contact at point B and the end of the resistance element at point C. A linear relationship exists between the input voltage Xt, output voltage Xi and the distance BC.
ANGULAR POTENTIOMETER Rotary or angular potentiometers measure angular displacement .
This presentation gives the information about 'vibration measuring instruments' covering syllabus of Unit-5 of Theory of vibrations or mechanical vibrations for BE course under VTU, Belgaum. This presentation is prepared by Hareesha N G, Asst. Prof, Dept of Aerospace, DSCE, B'Lore-78.
Subject: Mechanical Engineering Measurement. (I-Scheme III Sem. Diploma in Mechanical Engg.)
Ch. no. 2. displacement, force & torque measurement.
Department of Mechanical Engg.
Babasaheb Phadtare Polytechnic, Kalamb-Walchandnagar.
Prepared by Prof. Amol Yashwant Kokare Sir
LINEAR POTENTIOMETER Potentiometers are electrical devices which are a form of variable resistance.
It consists of a sliding contact which moves over the length of a resistance element. This sliding contact connects to a plunger, which links to the object whose displacement is to be measured.
Referring to the electrical circuit shown here, An input voltage Xt is applied across the whole resistance element, at points A and C. The output voltage, Xi , is measured between the sliding contact at point B and the end of the resistance element at point C. A linear relationship exists between the input voltage Xt, output voltage Xi and the distance BC.
ANGULAR POTENTIOMETER Rotary or angular potentiometers measure angular displacement .
This presentation gives the information about 'vibration measuring instruments' covering syllabus of Unit-5 of Theory of vibrations or mechanical vibrations for BE course under VTU, Belgaum. This presentation is prepared by Hareesha N G, Asst. Prof, Dept of Aerospace, DSCE, B'Lore-78.
Subject: Mechanical Engineering Measurement. (I-Scheme III Sem. Diploma in Mechanical Engg.)
Ch. no. 2. displacement, force & torque measurement.
Department of Mechanical Engg.
Babasaheb Phadtare Polytechnic, Kalamb-Walchandnagar.
Prepared by Prof. Amol Yashwant Kokare Sir
Please refer this file just as reference material. More concentration should on class room work and text book methodology.
Introduction to Mechanical Measurement
Functional elements of measurement system-
Basic Functional Elements-
1.Primary sensing element
2. Variable conversion element
3. Variable manipulation element
4. Data transmission element
5. Data storage and playback element
6. Data presentation element
Auxiliary elements-
1. calibration element
2. External power element
3. feedback element
4.microprocessor element
This presentation content various types of strain gauges, derivation of gauge factor.
Various course having subject as instrumentation, measuring devices, contenting strain measurement as a topic so introduction to strain gauge can help to understand the topic.
A thermocouple is a temperature-measuring device consisting of two dissimilar conductors that contact each other at one or more spots. It produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
1. THERMOCOUPLE
∙ Principle of Operation
∙ Materials Used
∙ Advantages
∙ Applications
∙ Comparison with RTD
∙ Limitations
By
AnandBongir
GirjashankarMishra
2. A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference.
3. Principle of Operation
Thermocouples are based on the principle that two wires made of dissimilar materials connected at either end will generate a potential between the two ends that is a function of the materials and temperature difference between the two ends (also called the Seebeck Effect).
4. Seebeck Effect
5.
6. Materials Used
Type K:
Chromel – Alumel
• Range: −200 °C to +1350 °C
• Sensi: 41 µV/°C
Type J:
Iron – Constantan
• −40 to +750 °C
• 55 µV/°C
Type E:
Chromel – Constantan
• 401 to 900° C
• 68 µV/°C
Type N:
Nicrosil – Nisil
• >1200 °C
• 39 µV/°C
7. Advantages
It is rugged in construction
Covers a wide temperature range
Using extension leads and compensating cables, long transmission distances for temperature measurement possible. This is most suitable for temperature measurement of industrial furnaces
Comparatively cheaper in cost
Calibration can be easily checked
Offers good reproducibility
High speed of response
Satisfactory measurement accuracy
8. Limitations
For accurate temperature measurements, cold junction compensation is necessary
The emf induced versus temperature characteristics is somewhat nonlinear
Stray voltage pickup is possible
In many applications, amplification of signal is required
9. Applications
Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process.
Gas-fed heating appliances such as ovens & water heaters.
In the testing of prototype electrical and mechanical apparatus
it is related to the subject dynamics of machinery in that measurement of vibration, instrument used for vibration measurement, control of vibration and related part is covered
Generalized Measurement System is a measuring system exists to provide information about the physical value of some variable being measured. In this presentation, generalized measurement system, its elements, classification of instruments, classification of measurement methods, difference between mechanical and electrical measurement systems, input output characteristics are described.
Dynamo meters are the electronic devices that are widely used to the purpose of force analysis in various field of operations. There is various types of dynamometers such as
Lathe tool dynamometer
Milling tool dynamometer
Drilling tool dynamometer
Please refer this file just as reference material. More concentration should on class room work and text book methodology.
Introduction to Mechanical Measurement
Functional elements of measurement system-
Basic Functional Elements-
1.Primary sensing element
2. Variable conversion element
3. Variable manipulation element
4. Data transmission element
5. Data storage and playback element
6. Data presentation element
Auxiliary elements-
1. calibration element
2. External power element
3. feedback element
4.microprocessor element
This presentation content various types of strain gauges, derivation of gauge factor.
Various course having subject as instrumentation, measuring devices, contenting strain measurement as a topic so introduction to strain gauge can help to understand the topic.
A thermocouple is a temperature-measuring device consisting of two dissimilar conductors that contact each other at one or more spots. It produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
1. THERMOCOUPLE
∙ Principle of Operation
∙ Materials Used
∙ Advantages
∙ Applications
∙ Comparison with RTD
∙ Limitations
By
AnandBongir
GirjashankarMishra
2. A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference.
3. Principle of Operation
Thermocouples are based on the principle that two wires made of dissimilar materials connected at either end will generate a potential between the two ends that is a function of the materials and temperature difference between the two ends (also called the Seebeck Effect).
4. Seebeck Effect
5.
6. Materials Used
Type K:
Chromel – Alumel
• Range: −200 °C to +1350 °C
• Sensi: 41 µV/°C
Type J:
Iron – Constantan
• −40 to +750 °C
• 55 µV/°C
Type E:
Chromel – Constantan
• 401 to 900° C
• 68 µV/°C
Type N:
Nicrosil – Nisil
• >1200 °C
• 39 µV/°C
7. Advantages
It is rugged in construction
Covers a wide temperature range
Using extension leads and compensating cables, long transmission distances for temperature measurement possible. This is most suitable for temperature measurement of industrial furnaces
Comparatively cheaper in cost
Calibration can be easily checked
Offers good reproducibility
High speed of response
Satisfactory measurement accuracy
8. Limitations
For accurate temperature measurements, cold junction compensation is necessary
The emf induced versus temperature characteristics is somewhat nonlinear
Stray voltage pickup is possible
In many applications, amplification of signal is required
9. Applications
Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process.
Gas-fed heating appliances such as ovens & water heaters.
In the testing of prototype electrical and mechanical apparatus
it is related to the subject dynamics of machinery in that measurement of vibration, instrument used for vibration measurement, control of vibration and related part is covered
Generalized Measurement System is a measuring system exists to provide information about the physical value of some variable being measured. In this presentation, generalized measurement system, its elements, classification of instruments, classification of measurement methods, difference between mechanical and electrical measurement systems, input output characteristics are described.
Dynamo meters are the electronic devices that are widely used to the purpose of force analysis in various field of operations. There is various types of dynamometers such as
Lathe tool dynamometer
Milling tool dynamometer
Drilling tool dynamometer
The Piezoelectric transducer is an electroacoustic transducer use for conversion of pressure or mechanical stress into an alternating electrical force. It is used for measuring the physical quantity like force, pressure, stress, etc., which is directly not possible to measure.The piezo transducer converts the physical quantity into an electrical voltage which is easily measured by analogue and digital meter.
The piezoelectric transducer uses the piezoelectric material which has a special property, i.e. the material induces voltage when the pressure or stress applied to it. The material which shows such property is known as the electro-resistive element
the above PPT will give a brief idea of the measuring device used in the field of Mechanical Engineering with images related to the topics in the field of measurement.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
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Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2. Introduction
Piezoelectric effect:-
The piezoelectric effect refers to a change in electric polarization that
is produced in certain materials when they are subjected to
mechanical stresses. This stress-dependent change in polarization
manifests as a measurable potential difference across the material.
Referred to as the direct piezoelectric effect, this phenomenon is
observable in many naturally available crystalline materials, including
quartz, Rochelle salt, and even human bone. Engineered materials,
such as lithium niobate and lead zirconate titanate (PZT), exhibit a
more pronounced piezoelectric effect.
3. An accelerometer is an electromechanical device used to measure
acceleration forces. Such forces may be static, like the continuous force
of gravity or, as is the case with many mobile devices, dynamic to sense
movement or vibrations. Acceleration is the measurement of the
change in velocity, or speed divided by time.
4. piezoelectric accelerometer
A piezoelectric accelerometer is an accelerometer that employs the piezoelectric
effect of certain materials to measure dynamic changes in mechanical variables (e.g.,
acceleration, vibration, and mechanical shock). As with all accelerometer,
piezoelectric accelerometers convert one form of energy into another and provide an
electrical signal in response to a quantity, property, or condition that is being
measured.
As with all accelerometer, piezoelectric accelerometers convert one form of energy
into another and provide an electrical signal in response to a quantity, property, or
condition that is being measured. Using the general sensing method upon which all
accelerometers are based, acceleration acts upon a seismic mass that is restrained by a
spring or suspended on a cantilever beam, and converts a physical force into an
electrical signal. Before the acceleration can be converted into an electrical quantity it
must first be converted into either a force or displacement. This conversion is done via
the mass spring system shown in the figure to the right.
5. Working Principle
The piezoelectric accelerometer work on the principle of piezoelectric effect.
When mechanical stress or forces are applied to some materials along certain
planes, they produce electric voltage. This electric voltage can be measured
easily by the voltage measuring instruments, which can be used to measure the
stress or force.
The physical quantities like stress and force cannot be measured directly. In
such cases the material exhibiting piezoelectric accelerometer can be used. The
stress or the force that has to be measured is applied along certain planes to
these materials. The voltage output obtained from these materials due to
piezoelectric effect is proportional to the applied stress or force. The output
voltage can be calibrated against the applied stress or the force so that the
measured value of the output voltage directly gives the value of the applied
stress or force. In fact the scale can be marked directly in terms of stress or
force to give the values directly.
The voltage output obtained from the materials due to piezoelectric effect is
very small and it has high impedance. To measure the output some amplifiers,
auxiliary circuit and the connecting cables are required.
6.
7. Materials used for the Piezoelectric Accelerometer
There are various materials that exhibit piezoelectric effect as
mentioned above. The materials used for the measurement purpose
should posses desirable properties like stability, high output,
insensitive to the extreme temperature and humidity and ability to be
formed or machined into any shape. But none of the materials
exhibiting piezoelectric effect possesses all the properties. Quartz,
which is a natural crystal, is highly stable but the output obtained from
it is very small. It also offers the advantage of measuring very slowly
varying parameter as they have very low leakage when they are used
with high input impedance amplifiers.
8. Advantages of Piezoelectric accelerometer
Every devise has certain advantages and limitations. The piezoelectric
accelerometer offer several advantages as mentioned below:
1) High frequency response: They offer very high frequency response
that means the parameter changing at very high speeds can be sensed
easily.
2) High transient response: The piezoelectric accelerometer can detect
the events of microseconds and also give the linear output.
3) High output: They offer high output that be measured in the
electronic circuit.
4) The piezoelectric accelerometer are small in size and have rugged
construction.
9. Limitations of Piezoelectric Accelerometer
Some of the limitations of piezoelectric accelerometer are:
1) Output is low:- The output obtained from the piezoelectric
accelerometer is low, so external electronic circuit has to be connected.
2) High impedance:- The piezoelectric crystals have high impedance so
they have to be connected to the amplifier and the auxiliary circuit,
which have the potential to cause errors in measurement. To reduce
these errors amplifiers high input impedance and long cables should
be used.
3) Forming into shape:- It is very difficult to give the desired shape to
the crystals with sufficient strength.
10. Applications of the Piezoelectric accelerometer
1) The piezoelectric accelerometer are more useful for the dynamic
measurements, i.e. the parameters that are changing at the fast rate. This is
because the potential developed under the static conditions is not held by the
instrument. Thus piezoelectric crystals are primarily used measurement of
quantities like surface roughness, and also in accelerometers and vibration
pickups.
2) For the same reasons they can be used for studying high speed phenomenon
like explosions and blast waves. They are also used in aerodynamic shock tube
work and seismograph (used for measurement of acceleration and vibration in
rockets).
3) Many times the piezo sensors or accelerometer are used along with the strain
gauges for measurement of force, stress, vibrations, etc.
4) The automotive companies used piezoelectric accelerometer to detect
detonations in the engine blocks.
5) Piezoelectric accelerometer are used in medical treatment, Sonchemistry and
industrial processing equipments for monitoring the power.
11. Reference
1) Book: Mechanical and Industrial Measurements by R. K. Jain, Khanna
Publishers
2) Mechanical Measurements by Thomas G. Beckwith and N. Lewis Buck
3) http://en.wikipedia.org/wiki/Piezoelectricity