2. The role of experimentation in the teaching of subjects such as INSTRUMENTATION &
CONTROL LAB is well established. Properly designed experiments reinforce the teaching of
basic principles taught in lecture classes and help students to understand these principles more
thoroughly. There are other advantages too:
i. Students learn to use basic instruments and get acquainted with the method used
to measure various physical quantities.
ii. They also study techniques of analyzing experimental data and presenting them
in a proper form.
4. i
SYLLABUS OF INSTRUMENTATION LAB PRESCRRIBEDBY JNTUK
Note: MINIMUM OF 8 EXPERIMENTS TO BE DONE
1. Calibration of pressure gauge.
2. Calibration of transducer for temperature measurement.
3. Study and calibration of LVDT transducer for displacement measurement.
4. Calibration of strain gauge.
5. Calibration of thermocouple.
6. Calibration of capacitive transducer.
7. Study and calibration of photo and magnetic speed pickups.
8. Calibration of resistance temperature detector.
9. Study and calibration of a rotameter.
10. Study and use of a seismic pickup for the measurement of vibration
amplitude of an engine bed at various loads.
11. Study and calibration of Mcleod gauge for low pressure.
5. ii
LIST OF EXPERIMENTS
Name of the Experiments Page No
1. Calibration of Capacitive Transducer for angular displacement. 01 - 04
2. Study and calibration of Photo and Magnetic speed pickups for speed 05 - 09
3. Study of Resistance Temperature Detector for temperature measurement 10 - 13
4. Calibration of Pressure Gauges 14 - 17
5. Study and calibration of LVDT transducer for displacement measurement. 18 - 21
6. Calibration of Thermocouple for temperature measurement. 22 - 25
7. Study and calibration of a Rotometer for flow measurement. 26 - 29
8. Study and use of a seismic pickup for the measurement of vibration
amplitude of an engine bed at various loads 30 - 32
9. Calibration of strain gauge for temperature measurement 33 - 35
10. Study and calibration of Mcleod gauge for low pressure. 36 – 37
6. iii
Course Outcomes
Metrology
&Instrumenta
tion Lab
The student shallbe measuring the various parameters like length, height, angle,
displacement, flatness etc., by using various instruments like vernier calipers, micrometer,
dial indicator, etc.
The student shallbe able to measure the threads,gear tooth profiles and surface roughness
using appropriate instruments and analyze the data.
Conduct, Analyse,interpret, and present measurement data from measurements experiments
by Engineering principles.
The student shallbe able to check alignment of various components in various mechanisms
using advanced scientific tools.
Able to select proper measuring instrument and know requirement of calibration, errors in
measurement
7. iv
Program Outcomes (POS)
Engineering Graduates will be able to:
1. Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and an
engineering specialization to the solution of complex engineering problems.
2. Problem analysis: Identify, formulate, review research literature, and analyze complex engineering
problems reaching substantiated conclusions using first principles of mathematics, natural sciences, and
engineering sciences.
3. Design/development of solutions: Design solutions for complex engineering problems and design system
components or processes that meet the specified needs with appropriate consideration for the public health
and safety, and the cultural, societal, and environmental considerations.
4. Conduct investigations of complex problems: Use research-based knowledge and research methods
including design of experiments, analysis and interpretation of data, and synthesis of the information to
provide valid conclusions.
5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern engineering
and IT tools including prediction and modeling to complex engineering activities with an understanding of
the limitations.
6. The engineer and society: Apply reasoning informed by the contextual knowledge to assess societal,
health, safety, legal and cultural issues and the consequent responsibilities relevant to the professional
engineering practice.
7. Environment and sustainability: Understand the impact of the professional engineering solutions in
societal and environmental contexts, and demonstrate the knowledge of, and need for sustainable
development.
8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of the
engineering practice.
9. Individual and team work: Function effectively as an individual, and as a member or leader in diverse
teams, and in multidisciplinary settings.
8. v
10. Communication: Communicate effectively on complex engineering activities with the engineering
community and with society at large, such as, being able to comprehend and write effective reports and
design documentation, make effective presentations, and give and receive clear instructions.
11. Project management and finance: Demonstrate knowledge and understanding of the engineering and
management principles and apply these to one‟s own work, as a member and leader in a team, to manage
projects and in multidisciplinary environments.
12. Life-long learning: Recognize the need for, and have the preparation and ability to engage in independent
and life-long learning in the broadest context of technological change.
9. vi
PROGRAM SPECIFIC OUTCOMES (PSOs)
The following are the Program Specific Outcomes of Engineering Graduates:
PSO1: DEVELOP ENERGY EFFICIENT SYSTEM: An ability to design, develop and test an
energy efficient system for required engineering applications.
PSO2: DESIGN TOOLS: An ability to use CAD/CAM/CAE tools to solve engineering problems.
PSO3: PROJECT DEVELOPMENT: An ability to design and execute the plan to manufacture
components / assembly.
11. viii
ACCESSORIES OF EQUIPMENTS
1. Capactive Transducer.
2. Magnetic sensor and Light sensor.
3. Resistance Temperature.(RTD)
4. Dead weight pressure gauge.
5. Linear variable differential transducer. (LVDT)
6. Thermocouple.
7. Rotometer.
8. Vibrometer.
9. Strain gauge.
10. Mcleod gauge.
12. x
GENERAL INSTRUCTIONS TO STUDENTS
1. Keep the variac to zero voltage position before starting the experiments.
2. Increase voltage slowly.
3. Do not increase voltage above 150 V.
4. Keep all the assembly undisturbed.
5. Operate selector switch of temperature indicator slowly.
6. Operate all the switches and controls gently.
7. Always ensure that the equipment is earthed properly before switching on the
supply.
13. x
INTRODUCTION
Introduction to Transducers and Measurement systems:
Transducer:
Transducer is a device which converts one form of energy into another form like
Electrical to Mechanical, Mechanical to Electrical, Thermal to Electrical and etc.,
Emphasis in the instrumentation trainers will be directed toward electronic instrumentation
systems rather than mechanical systems. In most cases electronic systems provide better data
more accurately completely characterize the design or process being experimentally evaluated.
Also the electronic system provides an electrical out put signal that can be used for automatic
data reduction or for the control of the process. These advantage of the electronic
measurement system over the mechanical measurement system have initiated and sustained
trend instrumentation toward electronicmethods.
An attempt is made through these “Instrumentation trainer kits” to make as easy as possible
for the students to learn about the electronic instrumentation system and various transducers
used for the measurement of mechanical component. The instrumentation tutor panels are
design in such a way that block diagrams of the stages of electronic instrumentation system
are clearly pictured on them. This makes the instrumentation tutor self explanatory and also the
best teaching aid for engineeringstudents.
Since the instrumentation tutors are not instrument as a whole the accuracy of the measurement
cannot be claimed. It is very clear that the instrumentation tutors are only for demonstration
purpose and cannot be used for any external measurement other than conducting experiments.
THE ELECTRONIC INSTRUMENTATION SYSTEM.
The complete electronic instrumentation system usually contains six sub systems or
elements the TRANSDUCER is a device that convert a change in the mechanical or thermal
quantity being measured into a change of an electrical quantity. Example strain gauges
bonded in to an specimen, gives out electrical out put by changing its resistance when material
is strained.
The POWER SUPPLY provides the energy to drive the Transducers, example differential
transformer, which is a transducer used to measure displacement required an AC voltage
supply to excite thecoil.
SIGNAL CONDITIONERS are electronic circuits the convert, compensate, or manipulate the
out put from in to a more usable electronic quantity. Example the whetstone bridge used in
the strain transducer converts the change in resistance. AR to a change in the resistance AE.
AMPLIFIERS are required in the system when the voltage out put from the transducer signal
conditioner combination is small. Amplifiers with game of 10 to 1000 are used to increase
their signals to levels they are compatible with the voltage – measuring devices.
14. x
RECORDERS are voltage measuring devices that are used to display the measurement in a
form that can be read and interpreted Digital/Analog voltmeters are often used to measure static
voltages.
DATA PROCESSORS are used to convert the out put signals from the instrument system into data that
can be easily interpreted by the Engineer. Data processors are usually employed where large amount of
data are being collected and manual reduction of these data would be too time consuming and costly.
15. I&CS LAB Capacitive Transducer
[Type text]
AIM:
Calibration of capacitive transducer for measurement of angular displacement.
THEORY:
The principle of change of capacitance with change in area of overlap may be employed
for the measurement of angular displacement. A simple capacitor transducer for the
measurement of angular displacement is shown in fig (a).
It consists of one fixed plate and movable plate. The movable plate is attached to
the object whose angular displacement is to be measured. Angular displacement of the
movable plate changes the overlapping area, there by changing the capacitance of the
capacitor. The capacitance is maximum when two plates overlap completely i.e. when
θ=1800.
Capacitance of the transducer of this type is
,
CALIBRATION:
The process of finding the error of an instrument and correcting the error by comparing
the instrument against a known standard is called calibration. Calibration procedure
involves the comparison of a instrument with either (a) a primary standard (or) (b) a
secondary standard with a higher accuracy than the instrument to be calibrated. If the
instrument has been aged, repaired (or) modified at any time, then it is necessary to carry
out calibratio0n of instrument.
While carrying calibration of instrument one should keep the following points.
(i) Calibration of an instrument must be carried under which it is to be operated while
in service.
(ii) Calibration of an instrument should be done and plot the calibration curve which
gives information about the error of the instrument linearity, repeatability etc.
Now the capacitive transducer is calibrated with the known standard of protractor. The
angular displacement known by protractor is compared with angular displacement when
EXPERIMENT NO 1
CALIBRATION OF CAPACITIVE TRANSDUCER FOR MEASUREMENT OF
ANGULAR DISPLACEMENT
16. I&CS LAB Capacitive Transducer
[Type text]
by capacitive transducer at different readings and compared, and plot the calibration
curve, the experimental test setup is shown in figure below.
1,2 are knob for adjustment for zero
Figure: Experimental test setup
Fig(a) Capacitive Transducer for measuring the angular Displacement
17. I&CS LAB Capacitive Transducer
[Type text]
GRAPH:
Where,
X = Angular displacement shown by protractor
Y = Angular displacement shown by Capacitive Transducer
TOOLS REQUIRED:
1. Capacitive transducer with digital indicator (or) trainer.
2. Power source.
PROCEDURE:
1. Connect the capacitance trainer to power supply.
2. Adjust the trainer with zero by adjusting the knob 1.
3. Rotate the knob over a protractor, so the change in position of knob leads to change in
capacitance and digital display will show the value.
4. Take the different readings at different angular rotations.
5. Compare the values and plot the calibration curve.
PRECAUTIONS:
1. Readings are to be taken at steady state conditions.
2. Readings are to be taken from instrument, when it is free from vibration, air etc.
3. Reading are to be taken without parallax error.
4. Before starting the equipment, the electrical connection will be verified and adjust the
instrument with zero value.
OBSERVATION TABLE
Sl.No Angular displacement
shown by protractor in
degrees (X)
Angular displacement
shown by capacitive
transducer in degrees (Y)
Error of
measurement
Correction
1
2
3
4
19. I&CS LAB Photo & Magnetic Speed pick ups
[Type text]
AIM:
Study and calibration of photo and magnetic speed pick ups for the measurement of
speed.
THEORY:
Photo pick up of speed measure:
Description:
1. A shaft carrying a disc which has number of equidistant holes on its periphery.
2. A light source on one side of the disc and a light sensor (photo cell) on the opposite
side of the light source.
3. A display device.
Operation:
The shaft of the tachometer is connected to the speed source, the disc starts
rotating. As the disc rotates, the lights possess through the holes for some time and the
rest is obstructed by the opaque disc. Hence only when a hole is present, the light falls on
the light sensor. Thus the intermits light falling on the photocell produces voltage pulses.
The frequency of this voltage pulse is a measure of the speed of the disc. The output is
obtained on frequency measuring unit.
Magnetic pick up of speed measurement:
Description:
1. A shaft on which a toothed wheel is mounted.
2. A permanent magnet with a coil wound.
3. A pulse shaper/amplifier.
4. An electronic counter (or) frequency meter.
Operation:
When the shaft of the tachometer is connected to the source whose speed
is to be measured, the shaft and hence the toothed wheel rotates.
As the toothed wheel rotates, the magnetic flux linking the magnet and coil changes (ie;
there is a change in the reluctance of the magnetic field).
Due to this, a voltage is induced in the coil with a certain frequency. This frequency is
proportional to the speed of the rotating wheel and hence the speed of source.
The frequency of pulses depends on the number of teeth on the wheel.
EXPERIMENT NO 2
STUDY & CALIBRATION OF PHOTO & MAGNETIC SPEED PICK UP FOR
MEASUREMENT OF SPEED
20. I&CS LAB Photo & Magnetic Speed pick ups
[Type text]
The pulses that are generated are not uniform and well shaped. Hence they are shaped and
amplified.
The output is obtained on a frequency measurement.
Photo Pick up Speed Measurement
Magnetic Measurement ( Pick up of Speed)
21. I&CS LAB Photo & Magnetic Speed pick ups
[Type text]
CALIBRATION:
The process of finding the error of an instrument and correcting the error by comparing
the instrument against a known standard is called calibration. Calibration procedure
involves the comparison of a particular instrument with either (a) a primary standard
accuracy than the instrument to be calibrated. (b) a secondary standard with a higher
accuracy than the instrument to be calibrated.
If the instrument has been adjusted, aged, repaired (or) modified at any time, then it is
necessary to carry out calibration of the instrument. While carrying calibration of an
instrument the following points should be considered.
1. Calibration of instrument must be carried out in the same environmental conditions
under which it is to be operated while in service.
2. Calibration of an instrument should be done with values of measured and plot the
calibration curve which gives information about the error of the instrument, and also
linearity, hysterics and repeatability of instrument.
Now the magnetic pick up for speed measurement should be calibrated with photo pickup
with the experimental test set up as shown below.
Model Graph
Where,
X = speed of motor shown by photo pick up
Y = speed of motor shown by magnetic pick up
TOOLS REQUIRED:
1. Photo pick up Sensor.
2. magnetic pick up Sensor.
22. I&CS LAB Photo & Magnetic Speed pick ups
[Type text]
1 = Knob for photo pick up
2 = Knob for magnetic pick up
3 = Change over switch
Experimental Test Setup
PROCEDURE:
1. Connect the motor to electrical connection.
2. Connect the speed measurement trainer to electrical connection.
3. Verify and set the zero value on trainer before starting the equipment.
4. Give power to motor, as its speed increases note down the speed with photo pick and
magnetic pickup by actuating the change over switch.
5. Note down the readings and draw calibration curve.
PRECAUTIONS:
1. The readings are to be taken at steady state conditions of the instrument.
2. The readings are to be observed without parallax error.
3. During noting the readings, the setup is free from vibration, air etc.
4. The electrical connection should be properly connected to instrument.
23. I&CS LAB Photo & Magnetic Speed pick ups
[Type text]
OBSERVATION TABLE
S.NO. Speed of the motor shown
by the photo pick up in
rpm (X)
Speed of the motor shown
by the magnetic pick up in
rpm (Y)
Error of
measurement
Correction
1
2
3
4
5
Result:
24. I&CS LAB RTD
[Type text]
AIM:
Calibration of resistance-temperature-detector (RTD) for temperature measurement.
THEORY:
Most metals become more resistance to the passage of electric current as they
become hotter i.e., their resistance increase with increase in temperature. For most of the
metals the variation of resistance with temperature is given by
However, if the reference temperature is 'Zero‟, then the equation becomes,
The number of constants to be considered in the equation depends on the material, the
accuracy required, and the temperature range. In general platinum conductor requires 2
constants and nickel, copper conductors requires 3 constants, where as tungsten and
nickel alloy requires only on constant.
CONSTRUCTION & WORKING:
The resistive element of a RTD is generally a metal wire wound around an
electrically insulating material. Such as glass, ceramic (0r) mica. The wound element is
then placed in a protective enclosure made of protective cement as shown in fig (a).
In operation, when the resistive element is subjected to the environment whose
temperature is to be measured, the resistance of the elements gets changed. A bridge
circuit of either null type (or) deflection type is used to measure the change which is
indicative of the temperature.
CALIBERATION:
The process of finding the error of an instrument and correcting the error by
comparing the instrument against a known standard is called calibration.
Calibration procedure involves the comparison of a particular instrument with either (1)
Primary standard (or) (2) a secondary standard with a higher accuracy then the instrument
to be calibrated.
EXPERIMENT NO 3
CALIBRATION OF RESISTANCE TEMPERATURE DETECTOR (RTD) FOR
TEMPERATURE MEASUREMENTS
25. I&CS LAB RTD
[Type text]
If the device has been adjusted, aged, repaired, or modified at anoy time, then it is
necessary to carry out calibration of device (or) instrument. Carrying calibration of an
instrument one should keep the following points.
Figure (b) Experimental Test Setup
(i) Calibration of an instrument must be carried out in the same environmental
conditions under which it is to be operated while in service.
(ii) Calibration of an instrument should be done with values of the measured (I/P)
both in increasing and decreasing order to plot the calibration curve which gives
information about the error of the instrument. The extent of the instrument‟s
linearity, repeatability etc.,
Now the resistance temperature detector (RTD) is calibrated with against known primary
standard using liquid in glass thermometer as shown in fig(b).
26. I&CS LAB RTD
[Type text]
GRAPH
Where,
X = Temperature of hot fluid shown by thermometer
Y = Temperature of hot fluid shown by RTD
TOOLS REQUIRED:
1. Resistance-Temperature detector (RTD) with indicator.
2. Electric heater and
3. Liquid – in – glass thermometer.
Figure(a) Resistance Temperature Detector (RTD)
27. I&CS LAB RTD
[Type text]
PROCEDURE:
1. Connect the RTD indicator and electrical heater to electric power supply.
2. Keep the RTD in the water.
3. Place the thermometer at the same place in the hot water.
4. Note down the temperature of hot water shown by the mercury – in – glass
thermometer and RTD.
5. Plot the values and draw the calibration curve.
PRECAUTIONS:
1. Loose connections should be eliminated.
2. Readings are to be taken at steady state conditions.
3. The initial condition (set to zero if any) of the instrument is to be adjusted before
starting the experiment.
4. The experiment test set up should be free from vibrations and air.
OBSERVATION TABLE
S.NO. Temperature of hot fluid
shown by thermometer in
oC (X)
Temperature of hot fluid
shown by RTD in oC (Y)
Error of
measurement
Correction
1
2
3
4
5
Result:
28. I&CS LAB PRESSURE GUAGE
[Type text]
AIM:
Calibration of pressure gauge.
THEORY:
In this experiment, the calibration of bourdon‟s tube pressure gauge with the
diaphragm gauge is made.
Diaphragm gauge:
Diaphragm is a thin plate and it is clamped firmly around its edges. Diaphragms
are made of elastic metal alloys such as bronze, stainless steel and ferrous-nickel alloys.
A simple flat diaphragm gauge is shown below. The diaphragm gets deflected in
accordance with the pressure differential across the sides. It always deflects towards the
low pressure side. A electrical resistance strain gauge may installed in the diaphragm to
sense the deflection.
Bourdon’s tube pressure gauge:
It consists of an elastic tybe of steel (or) bronze which is of elliptical size and is
bent into a circular arc. This tube is called bourdon‟s tube which acts as a pressure
sensing element. One end of tube is closed and other end is open to allow the fluid into
the tube whose pressure is to be measured and to rotate the pointer on a graduated scale.
In operations, when the open end of the bourdon‟s tube is connected to the pressure point,
fluid under pressure enters the tube and the elliptical shape of the tube gradually changes
to circular shape. This change in shape causes the tube to staighten out slightly. The
change in curvature of the tube is transmitted through a system of gears to the pointer
which rotates on the graduated dial. The bourdon‟s tube pressure gauge is shown in fig
below.
CALIBRATION:
The process of finding the error of an instrument and correcting the error by
comparing the instrument against a known standard is called calibration.
Calibration procedure involves the comparison of a particular instrument with either (a) a
primary standard (or) (2) a secondary standard with a higher accuracy than the instrument
to be calibrated.
If the instrument has been adjusted, aged, repaired or modified at any time, then it is
necessary to carry out calibration of the instrument. While carrying calibration of the
instrument the following points should be considered.
1. Calibration of instrument must be carried out in the same environmental conditions
under which it is wo operated while in service.
EXPERIMENT NO 4
CALIBRATION OF PRESSURE GAUGE
29. I&CS LAB PRESSURE GUAGE
[Type text]
2. Calibration of an instrument should be done with values of measured and plot the
calibration curve which gives information about the error of the instrument, and also
linearity, hysterics and repeatability of instrument.
Now the bourdon‟s tube pressure gauge is to be calibrated until diaphragm gauge with
experimental setup shown below.
GRAPH
Where,
X = Pressure shown by diaphragm gauge
Y = Pressure shown by Bourdon‟s tube pressure gauge
TOOLS REQUIRED:
1. Pressure measurement test setup (air pump, Diaphragm gauge) with digital indicator
( pressure measurement trainer).
2. Bourdon‟s tube pressure gauge.
Figure (s) Diaphragm Gauge
P1 = Pressure to be measure
P2 = Atmospheric Pressure
30. I&CS LAB PRESSURE GUAGE
[Type text]
Experimental Test Setup
Figure (b) Bourdon‟s tube Pressure Gauge
PROCEDURE:
1. Connect pressure measurement trainer to electrical connection and initially adjusted
to the zero value.
2. Gauge which is to be calibrated is to be fixed to diaphragm gauge.
3. Air pressure is increased by air pump and the readings of pressure is to be noted with
diaphragm gauge and at the same time with bourdon‟s tube pressure.
4. Same procedure is continued for minimum four readings.
5. Note down the readings and plot the calibration curve.
31. I&CS LAB PRESSURE GUAGE
[Type text]
PRECAUTIONS:
1. The readings are to be taken at steady state condition of instrument.
2. The readings are to be observed without parallax error.
3. During noting the readings, the set up is free from vibration, air etc.,
4. The electrical connection should be properly connected to instrument (i.e., loose
connections should be avoided).
OBSERVATION TABLE
Sl.No. Pressure shown by
diaphragm gauge in
kg/cm2 (X)
Pressure shown by
bourdon‟s tube pressure
gauge in kg/cm2 (Y)
Error of
measurement
Correction
1
2
3
4
5
6
32. I&CS LAB LVDT
AIET 18 MECHANICAL DEPT.
AIM:
Study and calibration of LVDT transducer for displacement.
THEORY:
LVDT means linear variable differential transformer. The LVDT is used to
convey the linear motion of iron core into electrical signals. Whenever an iron core is
inducted in the magnetic field the change in inductance coil will be taken place.
LVDT is a three coil variable material inductance transducer. LVDT consists of a
secondary oil S1 and S2 which are symmetrically placed with respect to the primary oils as
shown in fig(a).
The two secondary coil are connected in series but are in opposite phase. The number of
turns in each secondary coil is some and are wound on a cylindrical former. A movable
soft iron core is made of high permeability nickel-iron of the material which is hydrogen
annealed and is attached to the body whose displacement is to be measured. The entire
assembly is placed inside a housing.
When an A.C current is supplied to primary coil and alternating magnetic field is
generated in the circuit. The magnetic field is distributed by an armature which is
connected to a moving body. A voltage is developed in the two secondary coil due to the
disturbance in the magnetic output is equal to the algebraic sum of the voltages developed
in the two secondary coils.
CALIBRATION:
The process of finding the errors of an instrument and correcting error by
comparing the instrument against a known standard is called calibration produce involves
the composition of a particular instrument with a higher accuracy than the instrument is
calibrated.
If the instrument has been aged, repaired or modified at any time then it is necessary to
carry out recalibration of the considered.
1. Calibration of an instrument must be carried out in the same environmental conditions
under which it is to be operated while in service.
2. Calibration of an instrument should be done with values as measured and plot the
calibration curve.
EXPERIMENT NO 5
STUDY & CALIBRATION OF LVDT TRANSDUCER FOR DISPLACEMENT
MEASUREMENT
33. I&CS LAB LVDT
AIET 19 MECHANICAL DEPT.
GRAPH:
OPERATION:
When the core is at the centre, the flux linkage with both the secondary coil are
the same and hence equivalent are induced in them given zero voltage is called
null position. When the core is moved to the left of the null position more magnetic field
linkage occurs with the windings and line with the windings therefore and the
O/P is the relation between O/P volume and core displacement is below.
S1 = Secondary
windings S1 =
Secondary windings
Figure ( ) Sectional view of LVDT
34. I&CS LAB LVDT
AIET 20 MECHANICAL DEPT.
(a) (b)
Differential O/P
ES = ES1- ES2
APPLICATION:
1. It is used to measure displacement from function of millimeter to few centimeters.
2. Used for measurement of position and negative displacements.
TOOLS REQUIRED:
1. LVDT with digital LVDT trainer and
2. Micrometer
Figure ( ) Experimental Setup of LVDT
35. I&CS LAB LVDT
AIET 21 MECHANICAL DEPT.
PROCEDURE:
1. Connect to the electrical terminals to LVDT terminal.
2. Adjust the LVDT trainer with zero correction.
3. Attach the micrometer to the LVDT.
4. Give the displacement of LVDT trainer by micrometer.
PRECAUTIONS:
1. The readings are to be taken without parallax error.
2. The readings are taken at environment free from calibration.
OBSERVATION TABLE:
S.NO Displacement shown by
micrometer in mm (X)
Displacement shown by
LVDT in mm (Y)
Error of measurement Correction
+ve displacement
1
2
3
4
-ve displacement
1
2
3
4
Result:
36. I&CS LAB CALIBRATION OF THERMOCOUPLE
[Type text]
AIM:
Calibrate the thermocouple for temperature measurement.
THEORY:
When two dissimilar metals are joined together as shown in figure with one
junction at temperature T1 and other junction at temperature T2 an emf will be generated
which is primarily an of junction temperature.
The phenomenon on which thermocouple is working is also called see beck effect.
According to IEC standards there are number of thermocouple namely Type „T‟, Type
„K/N‟, Type „S‟, Type „E‟, Type „R‟, Type „B‟, Type „J‟ and Type „k‟. Among all, forpractical
use Type „J‟ and Type „K‟ are mostly used. The details of Type „J‟ and „K‟ are given below.
S.NO. Type Composition Temperature range ( c)
1 „J‟ Iron (+) Vs Constantan (-) -200 → +850 C
2 „K‟ Chromel (+) Vs Alumel (-) -200 → +1100 C
So as the junction temperature increases the emf induced is also increasing. The
temperature is directly proportional.
CALIBRATION:
The process of finding the error of an instrument and correcting the error by
comparing the instrument against a known standard is called calibration. Calibration
procedure involves the comparison of a particular instrument with either (1) a primary
standard or (2) a secondary standard with a higher accuracy than the instrument to be
calibrated.
If the instrument has been adjusted, aged, repaired or modified at any time, then it is
necessary to carry out calibration of the instrument while carrying calibration of an
instrument the following points should be considered.
1. Calibration of an instrument must be carried out in the same environmental conditions
under which it is to be operated while in service.
2. Calibration of an instrument should be done with values as measured and plot the
calibration curve which gives information about the error of the instrument, and also
linearity, hysterics and repeatability of instrument.
Now the thermocouple is calibrated by using the liquid-in-glass thermometer and its
experimental set up is shown in figure below.
EXPERIMENT NO 6
CALIBRATION THE THERMOCOUPLE FOR TEMPERATURE MEASUREMENT
37. I&CS LAB CALIBRATION OF THERMOCOUPLE
[Type text]
GRAPH
Where,
X = Temperature of hot fluid shown by thermometer
Y = Temperature of hot fluid shown by thermocouple
TOOLS REQUIRED:
1. Thermocouple with electronic indicator (thermocouple trainer).
2. Liquid-in-glass thermometer and
3. Electric heater.
Simple Thermocouple
38. I&CS LAB CALIBRATION OF THERMOCOUPLE
[Type text]
PROCEDURE:
1. Connect the thermocouple trainer to electrical connection.
2. Select the „J‟ type (or) „K‟ type thermocouple by actuating the selector knob.
3. Keep the selected thermocouple in water at ambient temperature.
4. Observe the temperature of water with liquid-in-glass thermometer and digital
temperature display or thermocouple trainer.
5. Correct the values to same temperature.
6. The temperature of water is to be increased by heater and find the temperature of hot
water by thermocouple and liquid-in-glass thermometer instantly.
7. Repeat the experiments to take minimum four readings.
8. Note down the readings and plot the calibration curve.
PRECAUTIONS:
1. The readings are to be taken at steady state conditions of the instrument.
2. The readings are to be observed without parallax error.
3. During noting the readings, the setup is free from vibration, air etc.,
4. The electrical connection should be properly connected to instrument.
39. I&CS LAB CALIBRATION OF THERMOCOUPLE
[Type text]
OBSERVATION TABLE:
S.NO Temperature of hot fluid
shown by thermometer
in oC (X)
Temperature of hot fluid
shown by thermocouple in
oC (Y)
Error of
measurement
Correction
1
2
3
4
5
Result:
40. I&CS LAB ROTOMETER
[Type text]
AIM:
Study and calibration of a rotometer for flow measurement.
THEORY:
Rotometer is used to measure the flow. It is also known as variable area meter. It
is the linear characteristics flow measuring instrument. It consists of two parts (a) taper
tube (b) float and the float is free to move in a tapered tybe. As flow takes place upward
through the tube, four forces act on the float
(1) A downward gravity force
(2) An upward buoyant force
(3) Pressure force and
(4) Viscous drag force
For a given rate of flow the float assumes a position in the tube, where the forces acting
on are in equilibrium. The position of float will define flow rate as the equation below.
Where,
Q = Volumetric rate of flow
Aw = Area of the annular orifice
D = Diameter of the tube when tip float at zero position.
b = change in tube diameter per unit change in height
d = maximum diameter of the float
y = height of the float above zero position
c = discharge coefficient
Vf = volume of the float.
= densities of float of liquid
Af = Area of float
EXPERIMENT NO 7
STUDY & CALIBRATION OF A ROTOMETER FOR FLOW MEASUREMENT
41. I&CS LAB ROTOMETER
[Type text]
OPERATION:
The process of finding the error of an instrument and correcting the error by
comparing the instrument against a known standard is called calibration. Calibration
procedure involves the competition of a particular instrument with either (a) a primary
standard or (b) a secondary standard with a high accuracy that the instrument to be
calibrated. The instrument is recalibrated if instrument is aged, repaired or adjusted while
carrying calibration of an instrument the following points kept in mind.
1. Calibration of an instrument must be carried out in the same environmental conditions
under which it is to be operated while in service.
2. Calibration of an instrument should be done with values as measured and plot the
calibration curve.
In calibration of rotometer, the flow of fluid of known secondary standard with the
reading of rotometer is done to the rotometer as the experimental setup is shown in
figure(2).
Model Graph:
Where,
X = Flow of water in lts/min
Y = Flow of water shown by rotometer in lts/min
TOOLS REQUIRED:
Rotometer with experimental test setup
43. I&CS LAB ROTOMETER
[Type text]
PROCEDURE:
1. Set the time (say 10sec) in digital timer.
2. Allow motor pump to run to collect the discharge in 10secs and note down the
readings.
3. Observe the readings of rotometer.
4. Compare the readings of rotometer as discharge in delivery tube in a stipulated time
(say 10sec) to find the error and also calculate the convection.
5. Draw the calibration curve of the rotometer for flow measurement.
ADVANTAGES:
1. Uniform flow rate over the entire range of the instrument.
2. Any corrosive liquids can be handled.
3. Condition of flow is readily visible in the tube.
DISADVANTAGES:
The meter must be installed in vertical position only for opaque liquids flowing the bob
will not be visible.
PRECAUTIONS:
1. Steady state conditions are applied while taking readings.
2. While taking readings, parallax error is to be eliminated.
OBSERVATION TABLE
S.NO. Discharge
of water
collected in
tube in litres
Time
taken in
sec(t)
Flow of
water in lts
/sec
Flow of
water in
lts/min
(X)
Flow of
water shown
by rotometer
(Y)
Error of
measurement
Correction
1
2
3
4
5
Result:
44. I&CS LAB VIBROMETER
[Type text]
AIM:
Study and use of seismic pickup for the measurement of vibration amplitude of an engine
bed at various loads (speeds).
THEORY:
A seismic pickup is used to find the amplitude of vibration. Vibration is generally
expressed in terms of displacement, velocity and acceleration. Hence, a vibrometer is a
accelerometer. The seismic pickup is used in seismic instrument. In seismic instrument, a
spring supported mass is mounted in a suitable housing with a sensing element provided
to detect the relative motion between mass and housing. Damping also provided by the
used of dashpot mounted between the seismic mass and housing. The seismic instrument
also provides with spring damping as shown in figure.
The displacement of vibrating body is obtained by the formula
And acceleration of vibrating body is obtained by the formula
Where,
t = any instant of time from t=0
= ratio of damping coefficient to critical damping coefficient
= undraped natural frequency
M = mass of seismic element
K = deflection constant for the support spring
g = gravitational constant = 9.81m/s2
Sso = amplitude of vibrating body
= exciting frequency
= phase angle of the system
= acceleration amplitude of the supporting member
= relative displacement amplitude between the mass and supporting member
EXPERIMENT NO 9
STUDY AND USE OF SEISMIC PICKUP FOR THE MEASUREMENT OF VIBRATION
AMPLITUDE OF AN ENGINE AT VARIOUS SPEEDS
45. I&CS LAB VIBROMETER
[Type text]
As the vibrating body is moving in simple harmonic excitation and
same is transferred to seismic mass by fixing housing firmly to vibrating body.
As a result of vibration, the seismic mass wave up to down and its movement causes the
resistance in secondary transducer which is the amplitude of vibrating member. The
spring and viscous damping is also used. To measure the vibration with accelerometer the
following experiment.
TOOLS REQUIRED:
1. Vibrating body
2. Accelerometer
Seismic Pickup
46. I&CS LAB VIBROMETER
[Type text]
PROCEDURE:
1. Fix the vibrating sensor (seismic pickup) firmly to vibrating body.
2. The amplitude of vibration is observed in accelerometer in the form of displacement,
velocity if acceleration by moving knob.
3. Change the speed and observe the change in vibration amplitude.
4. Same procedure for 5 different speeds (loads).
PRECAUTIONS:
Fix the vibration sensor firmly to the vibrating body.
OBSERVATION TABLE
Sl.No Speed of
m/c
(load)
Measurement of vibration amplitude
Displacement
in (mm)
Displacement
in (mts)
Velocity
in(cm/sec)
Velocity
in (m/sec)
Acceleration
in (m/sec2)
1 High
speed
less load
speed 1
2 Speed 2
3 Speed 3
4 Speed 4
high load
less
speed
Result:
47. I&CS LAB STRAIN GUAGE
[Type text]
AIM:
To determine the elastic constant (modulus of elasticity) of a cantilever beam
subjected to concentrated end load by using strain gauges.
THEORY:
A body subjected to external forces is in a condition of both stress and strain.
Stress can be directly measured but its effect. i.e. change of shape of the body can
be measured. If there is a relationship between stress and strain, stresses occurring
in a body can be computed if sufficient strain information is available. The constant
connecting the stress and strain in elastic material under the direct stresses is the
modulus of elasticity,
i.e. E=σ / є
the principle of the electrical resistance strain gauge was discovered by
Lord Kelvin, when he observed that a stress applied to a metal wire, besides changing
resistance strain gauges are made into two basic forms, bonded wire and bonded foil.
Wire gauges are sandwiched between two sheets thin paper and foil gauges are
sandwiched between two thin sheets of epoxy.
The resistance factor „R‟ of a metal depends on its electrical resistively, , its area,
a and the length l, according to the equation R = l / a.
Thus to obtain a high resistance gauge occupying a small area, the metal chosen has a
high resistively, a large number of grid loops and a very small cross sectional area.
The most common material for strain gauge is a copper - -nickel alloy known as
Advance
The strain gauge is connected to the material in which it is required to measure the
strain, with a thin coat of adhesive. Most common adhesive used is Eastman, Deco
Cement, etc. as the test specimens extends or contracts under stress in the direction
of windings, the length and cross sectional area of the conductor alter, resulting in a
corresponding increase or decrease in electrical resistance.
EXPERIMENT NO 9
MEASUREMENT OF STRAIN GUAGE
48. I&CS LAB STRAIN GUAGE
[Type text]
TOOLS REQUIRED:
A cantilever beam with concentrated end load arrangement, strain gauges and strain
indicator.
PROCEDURE:
STRAIN MEASUREMENT IN FOUR ARM MODES (FULL BRIDGE)
1. Switch on the instrument and leave 5 minutes to warm up.
2. Connect the sensor (Cantilever beam) to instrument by 4 core cable with
respective colored pins.
3. Keep the ARM selector switch to 4 positions.
4. Select the FUNCTION switch to GF position and adjust the display to read
500 by GF pot.
5. Select the FUNCTION switch to READ position and adjust the display to read
zero by zero pot.
6. Select the FUNCTION switch to CAL position and adjust the display to read
1000 by CAL pot.
Apply the load on cantilever beam, in steps of 100 grams and note down the readings.
TABULAR COLUMN FOR FULL BRIDGE
Sl. Load Strain Measured Bending Modulus of
No Applied
W (N)
Indicator
Reading Є
– micro
strain
Strain
Єm=є*10-6 / 4
stress.
σ = 6wl / bh
2
elasticity. E
= σ / Єm
(N/nm
2
)W N
STRAIN MEASUREMENT IN TWO ARM MODES (HALF BRIDGE)
1. Switch on the instrument and leave 5 minutes to warm up.
2. Connect the sensor (Cantilever beam) to instrument by 4 core cable with
respective colored pins.
3. Keep the ARM selector switch to 4 positions.
49. I&CS LAB STRAIN GUAGE
[Type text]
4. Select the FUNCTION switch to GF position and adjust the display to read 500
by GF pot.
5. Select the FUNCTION switch to READ position and adjust the display to read zero
by zero pot.
6. Select the FUNCTION switch to CAL position and adjust the display to read
1000 by CAL pot.
Apply the load on cantilever beam, in steps of 100 grams and note down the readings.
TABULAR COLUMN FOR HALF BRIDGE
Sl. Load Strain Measured Bending
stress. 2
σ = 6wl /
bh
Modulus of
No Applied Indicator Strain elasticity. E
W (N) Reading Є
– micro
strain
Єm=є*10
-6
/ 2
= σ / Єm
(N/nm
2
)W N
Result:
50. I&CS LAB MCLEOD GUAGE
[Type text]
Aim:
Low pressure measurement by McLeod gauge.
Theory:
Low pressure gauge:
Pressure less than 1mm of mercury are considered to be low pressure and
are expressed in either of two units, namely the torr and micron.1 torr is a pressure
equivalent to 1mm Hg at standard conditions., one micron is 10-3 torr through
common usage the term vacuum refers to any pressure below atmosphere (760mm
Hg).this pressure region is divided into 5 segments.
Low vacuum 760 torr to 25 torr
Medium vacuum 25 torr to 10-3 torr
High vacuum 10-3 torr to 10-6 torr
torr Very high vacuum 10-6 torr to 10-9 torr
Ultra high vacuum 10-9 torr and beyond
The pressure measuring devices for low pressure (vacuum) measurement can be
classified into 2 groups
Direct measurement:
Where in displacement deflection costs by the pressure is measured and
correlated to the applied pressure. This principle is incorporated in nanometers, spiral
bourdon tube; flat and corrugated diaphragms and capsules, manometers and gauges
are suitable to about 0.1 torr, bourdon gauges to 10 torr and diaphragm gauges to 10-
3 torr. Below these ranges, that use of indirect vacuum gauges is resorted
Tools required:
1. McLeod gauge
2. vacuum chamber
3. vacuum pump
EXPERIMENT NO 10:
STUDY AND CALIBRATION OF MCLEOD GAUGE FOR LOW PRESSURE
51. I&CS LAB MCLEOD GUAGE
[Type text]
Procedure:
1. Connect the tubes (pipes) from vacuum pump to vacuum chamber and vacuum
pump to McLeod gauge.
2. Open the outlet wall before starting the vacuum pump.
3. Close the outlet wall after starting the vacuum pump.
4. Keep the McLeod gauge in horizontal position before starting the vacuumpump.
5. Switch ON the vacuum pump.
6. See the reading in McLeod pump by varying perpendicular axis and note down the
readings
Observation Table:
S.No. McLeod Guage
1
2
3
4
5
Result: