metrology and measurements lab.pdf

` KONGU ENGINEERING COLLEGE

(Autonomous)

PERUNDURAI, ERODE - 638 052 DEPARTMENT OF MECHANICAL ENGINEERING

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LAB MANUAL

Degree : B.E

Year / Sem : II / IV

Course : Mechanical Engineering

Subject Code : 11ME508

Subject : METROLOGY AND MEASUREMENTS

LABORATORY


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11ME508 METROLOGY AND MEASUREMENTS LABORATORY

L T P C

0 0 3 1

Objective:

To familiarize the calibration and measurement process.

To study the characteristics of instruments.

To carry out the measurement of the length, angle, physical and thermal parameters of the

given object.

LIST OF EXPERIMENTS (Any 12 experiments) (Use slip gauges for calibration of length

measuring instruments)

LIST OF EXPERIMENTS /EXERCISES

1. Calibration of Vernier / Micrometer; static characteristic study. Measurement of

Components like V block etc.,.

2. Calibration of Internal micrometer and bore gauge; static characteristic study. Measurement

of components.

3. Calibration of Dial Gauge; static characteristic study; Use of dial gauge as measuring device

and comparator.

4. Calibration of Gear Tooth Vernier; static characteristics study; Measurement of gear tooth

thickness.

5. Calibration of LVDT and characteristic study; Use of LVDT as electronic comparator

6. Measurement/checking of Taper Angle using Bevel Protractor / Sine bar / Tool Makers

Microscope.

7. Measurement of straightness and flatness using autocollimator.

8. Measurement/checking of thread parameters using tool makers microscope/thread gauges

9. Checking the limits of dimensional tolerances using comparators (Mechanical / Pneumatic /

Electrical).

10. Calibration and characteristics study of dead weight pressure gauge

11. Dynamic characteristics study of glass thermometer- a first order instrument;

12. Use of CMM in metrology- Tracing the profile of a component and measurement of

dimensions

13. Machine alignment test (Lathe and special machines) like parallel and perpendicularity test.


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14. Use of Sampling Inspection & Control charts for Quality control.

15. Measurement of Force and torque(study experiment)

16. Measurement of Vibration / Shock(Demonstration experiment)

17. Study on measurement of light, sound, humidity, DBT, WBT, etc.

18. Temperature measurement using thermo couples, RTD etc.

TOTAL: 45

REFERENCES / MANUALS/SOFTWARE:

1. Jain, R. K., Engineering Metrology, Khanna Publishers, New Delhi, 2007.

2. Tayal, A. K, Instrumentation and Mechanical Measurements, Galgotia Publications, New

Delhi, 2006.


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PROGRAMME OUTCOMES

Definition and Validation of Course Outcomes and Programme outcomes

List the Course Outcomes (COs) and Programme Outcomes (POs)

The course outcomes and programme outcomes of Mechanical Engineering are listed as

below:

List of Course Outcomes (COs)

On completion of each course, the student will be able to

11ME508 Metrology and

Measurements Laboratory (MML)

i. demonstrate the knowledge/skill on standards,

calibration process and analyze the characteristics of

instruments

ii. demonstrate the knowledge/skill on measurement of

length, angle and form surface measurement.

Programme Outcomes:

A total of 13 program outcomes have been formulated for the Mechanical

Engineering program. These outcomes are defined as the skills and competencies students are

expected to have at the time of graduation. The Program Outcomes are:

Graduates will demonstrate

a. An ability to apply knowledge of mathematics, science and engineering.

b. An ability to design and conduct experiments, as well as to analyze and interpret data.

c. An ability to design a system, component, or process to meet desired needs within realistic

constraints.

d. An ability to function in multidisciplinary teams.

e. An ability to identify, formulate and solve engineering problems.

f. An understanding of professional and ethical responsibility.

g. An ability to communicate effectively.

h. The broad education necessary to understand the impact of engineering solutions in a

global and societal context.

i. Recognition of the need for and an ability to engage in continuous learning.

j. Knowledge on contemporary issues.


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k. An ability to use the techniques, skills and modern engineering tools necessary for

engineering practice.

l. An ability to work professionally in thermal, manufacturing and mechanical systems areas

including the design and realization of such systems with the use of computational tools.

m. An ability to demonstrate knowledge and understanding of economics/financial

management, project management and entrepreneurship skills.

Course: 11ME508 Metrology and Measurements Laboratory (MML)

PO /CO a b c D E f g h i j k l m

i)

ii)


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INDEX

S.No Date Content Page

No

Marks Awarded

Sign CoE

(10) Obs

(10) Rec

(10) Viva

(10) Total

40


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TOTAL

CoE - Conduct of Experiment

Obs - Observation

Rec - Record


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INSTRUMENTS LIST

S.NO NAME OF EQUIPMENT/INSTRUMENT

1 PORTABLE SURFACE ROUGHNESS TESTER

2 UNIVERSAL BEVEL PROTRACTOR

3 DIAL INDICATOR WITH MAGNETIC STAND

4 GEAR TOOTH VERNIER CALIPER

5 VERNIER DEPTH GAUGE

6 SCREW THREAD MICROMETERS

7 CO-ORDINATE MEASURING MACHINE

8 AUTOCOLLIMAETOR

9 FLOATING CARRIAGE MICROMETER

10 GEAR TOOTH VERNIER

11 TOOLMAKERS MICROSCOPE

12 TORQUE TRANSDUCER

13 LOAD CELL

14 GRANITE SURFACE PLATE

15 INSPECTION BENCH CENTER

16 ELEVTRONIC COMPARATOR (LVDT)

17 PITOT TUBE & PITOT CYLINDER

18 THERMOCOUPLES & THEROMETER

19 PROFILE PROJECTOR

20 AIR GUAGING EQUIPMENT

21 STRAIN GUAGE APPARATUS

22 VERNIER CALLIPER

23 VERNIER HEIGHT GAUGE

24 OUTSIDE MICROMETER

25 INSIDE MICROMETER

26 DEPTH MICROMETER


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S.no Name of equipment/Instrument

27 CYLINDER BORE GUAGE

29 VERNIER BEVEL PROTRACTOR

30 SINE BAR

31 SLIP GUAGE

32 FEELER GUAGE,SCREW PITCH GUAGE , RADIUS GUAGE

33 DIAL TEST INDICATOR

34 MAGNETIC BASE

35 V-BLOCK


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EXERCISE LIST

S.NO NAME OF EXPERIMENT Page

No

1. Calibration of dial gauge and measurement of component 11

2. Calibration of bore gauge, inside micrometer and measurement of the component 14

3. Calibration of depth gauge, vernier height gauge and measurement of the component 19

4. Calibration of LVDT and compare and check the dimensional tolerance using LVDT or ELECTRICAL COMPARATOR

23

5. Calibration of vernier caliper and micrometer and measurement of the given component 27

6. Measurement of taper angle by using sine bar 32

7. Calibration of gear tooth vernier and measurement of gear tooth thickness by gear tooth vernier caliper

35

8. Flatness and straightness checking using autocollimator

39

9. Measurement of the various dimensions by using Electronic comparator

42

10. Characteristics of first order instrument thermometer

45

11. Measurement of force using a proving ring 49

12. Power measurement using rope brake dynamometer 52

13. Calibration and draw the profile by using Profile projector 54

14. Angle measurement using bevel protractor 57

15. Hysterisis curve of a cantilever beam 61

16. Measuring cylinder and cone dimensions coordinate measuring machine 63


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Ex.No : Date:

CALIBRATION OF DIAL GAUGE AND MEASUREMENT OF COMPONENT

AIM

To calibrate the dial gauge using slip gauge and to measure the given components

using dial gauge.

APPARATUS REQUIRED

V - Block, Dial gauge with stand, Work piece, Slip gauges.

PROCEDURE

Calibration

1. The dial gauge is fitted to the stand to match the range of calibration of the dial

gauge.

2. Adjust the dial gauge reading to zero with respect to reference plane.

3. Insert the selected length standard (slip gauge) between the reference surface and the

dial gauge plunger .

4. Repeat step 3 for the incremental increaser standard input.

5. Note down output values for the each of standard inputs.

6. Calculate error in Dial Gauge.

7. Plot a graph of (i). Standard input vs Output and (ii). Standard input vs Error

8. Calculate sensitivity of the instrument.

Measurement

1. Without disturbing the calibration setup insert the work piece to be measured between

the reference surface and the Dial Gauge plunger.

2. Set a datum point or line.

3. Observe the Dial Gauge reading by moving the work piece to the edges for

measurement.


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4. Note down the reading of all the measurement.

5. Calculate compensating factor based on the error in the instrument.

6. Give a report of the work piece.

CALIBRATION OF DIAL GAUGE

S.No STD Dimension

in

mm

Reading From Dial Gauge Average

Error in

mm

R1 in mm R2 in mm R3 in mm mm deg

1

2

3

4

5

6

7

8

9

10

CHARACTERISTICS OF DIAL GAUGE

Range = mm

Span = mm

Least Count = mm

Linearity =

Output / Input =

% Linearity = %

Error/Bias = mm

Compensation Factor = mm

Sensitivity =


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MEASUREMENT OF SPECIMEN

S.No Parameter

measured

Observed Readings in mm

Compensating

factor in mm

Actual Readings in

mm

1

2

3

4

5

6

7

8

9

10

MODEL GRAPH

Output Error

Standard Input Standard Input

RESULT

Error of the instrument :

Sensitivity :

Lest count :


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Ex.No : Date:

CALIBRATION OF BORE GAUGE, INSIDE MICROMETER AND

MEASUREMENT OF THE COMPONENT

AIM

To calibrate the Bore Gauge and Inside Micrometer and also to measure the given

component.

APPARATUS REQUIRED

Vernier Calliper, Inside Micrometer, Bore gauge, Slip gauges, Component.

PROCEDURE

Calibration

1. Note down the range of instrument and the plunger displacement of the Bore Gauge.

2. Use a standard venier calliper as standard length and calibrate the gauges.

3. Note down the readings and plot the calibration graph.

4. Find the Least count, Error, Sensitivity of the instrument etc.,

Measurement

1. Insert the gauge into the given cylindrical work piece and carry out measurement at

different plane and at different position.

2. Draw a circularity graph and give a report of the circularity and taper of work pieces.

3. Give a report of the measurement.


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CALIBRATION OF THE BORE GAUGE & INSIDE MICROMETER

S.

No

Name of the

instrument Standard Input

values

in mm

Output values in mm Error in

mm I. II. III.

Average

values

1

BO

RE

GA

UG

E

2

3

4

6

7

8

9

10

11

INS

IDE

MIC

RO

ME

TE

R

12

13

14

15

16

17

18

19

20


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CHARACTERISTICS OF BORE GAUGE

Range :

Span :

Error : % Error

Compensation factor :

Least count =

CHARACTERISTICS OF INSIDE MICROMETER:

Range :

Span :


Compensation factor :

Least count :

Sensitivity :


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MEASUREMENT OF THE COMPONENT:

S.no Instrument

used Plane Position

Observed

Reading in mm

Compensation

Factor

Actual Reading

in mm

1

2

3

4

5

6

7

8

9

10

MODEL CALCULATION FOR BORE GAUGE:

Measured value = MSR + (VSC*LC)

Correct value = measured value + zero correction

MODEL CALCULATION FOR INSIDE MICROMETER:

Measure value = MSR + (PSR*LC)

Correct value = measured value + zero correction


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BORE GAUGE SENSITIVITY ANALYSIS:

RESULT:

Least count of the Instrument:

Error :

Sensitivity :

Attach the analysis report :

S.no

Input

value

In mm

Output value

Average value

Error in

mm

I II

Div Rad Div Rad Div Rad

1

2

3

4

5

6

7

8

9

10


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Ex.No : Date:

CALIBRATION OF DEPTH GAUGE, VERNIER HEIGHT GAUGE AND

MEASUREMENT OF THE COMPONENT

AIM

To calibrate the venire height gauge and depth gauge and to measure the given

component.

APPARATUS REQUIRED

Venire Height Gauge, Depth Gauge, Slip Gauge.

Calibration

1. With the help of slip gauges as standard, calibrate the gauges .

2. Plot a graph of (i) Standard Input vs Output and

(ii) Standard Input vs Error

3. Observe the characteristics like error, least count, sensitivity, etc.,

Measurement

1. Place the work piece and the gauge appropriately and carry out the measurement of

the job.

2. Prepare a report of the measurement and indicate the characteristics of the work

pieces.


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CALIBRATION OF DEPTH GAUGE

S.

No

Name of

instrument

Input value

in mm

Output value in mm Error in

mm I II III Average value

1

DE

PT

H G

AU

GE

2

3

4

5

6

7

8

9

10

CALIBRATION OF VERNIER CALIPER

S.

No

Input value

in mm

Output value in mm Error in

mm I II III Average value

11

VE

RN

IER

HE

IGH

T G

AU

GE

12

13

14

15

16

17

18

19

20


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CHARACTERISTICS OF DEPTH GAUGE:

Range :

Span :

Least count :

Sensitivity :

Error :

CHARACTERISTICS OF VERNIER HEIGHT GAUGE:

Range :

Span :

Least count :

Sensitivity :

Error :


Position MSR in mm PSR in Div OR=MSR+(PSR*LC) in mm CR=OR+ZC in mm


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Parameter

measured

MSR

in mm

VSR

in DIV

OR=MSR+(PSR*LC)

in mm

CR=OR+ZC

in mm

RESULT

Depth gauge

Least count of the Instrument :

Error :

Sensitivity :

Vernier Height gauge

Least count of the Instrument :

Error :

Sensitivity :


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Ex.No : Date:

CALIBRATION OF LVDT AND COMPARE AND CHECK THE DIMENSIONAL

TOLERANCE USING LVDT OR ELECTRICAL COMPARATOR

AIM

To calibrate the LVDT and to measure the incremental input.

APPARATUS REQUIRED

LVDT, Micrometer, Slip gauge.

PROCEDURE

Calibration

1. Note down the range and span of LVDT .

2. Chose suitable slip gauges to make enough number of readings for calibration.

3. Set the LVDT such that when the plunger is at the middle, indicating zero output.

4. Calibrate the LVDT on both side of plunger movement from its mean position.

5. Plot a graph of (i) Standard Input vs Output and

(ii) Standard Input vs Error

6. Calculate the error, least count, sensitivity, etc.,

Measurement

1. Insert the work piece to be measured, between the reference plane and LVDT plunger

with out disturbing the calibration setup.

2. Note down the indicated readings or the difference between the standard value and the

indicated reading if used as a comparator.

3. Make enough number of readings if used as a comparator and classify the items

indicated as accepted or rejected and produced a statistical report.

4. If its a measurement of a job, then produce a report of measurement.


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CALIBRATION OF LVDT

Basic size: Increment/Decrement =

S.NO STD Input Output

micron

Output

value in mm

Error

(m) mm m

1

2

3

4

5

6

7

8

9

10

Average error = m

Compensation factor = m

CHARATERISTICS OF ELECTRICAL COMPARATOR:

Range =

L.C =

Compensation factor =

Sensitivity = Change in output signal

Change in input signal

Accuracy = output-input

Input


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CHECKING OF COMPONENT: Compensation factor = m

Piece Readings Displayed/ Attribute outcome

in micron

Compensation

Factor

Actual Value

in micron

MODEL CALCULATION:

Error =

Compensation factor =

L.C =

Sensitivity = Change in output signal

Change in input signal

Accuracy = output-input

Input

Error =


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MODEL GRAPH:

Output Error

Standard Input Standard Input

RESULT:


Least count :

Sensitivity :

Accuracy :


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Ex.No : Date:

CALIBRATION OF VERNIER CALIPER AND MICROMETER AND

MEASUREMENT OF THE GIVEN COMPONENT

AIM

To calibrate and measure the given component by using vernier calliper and

micrometre.

APPARATUS REQUIRED

Slip gauges, Micrometer and Vernier Calliper.

PROCEDURE

Calibration

1. With the help of slip gauges as standard, calibrate the gauges.

2. Plot a graph of (i) STD Input vs Output and

(ii) Standard Input vs Error .

3. Observe the characteristics like error, least count, sensitivity etc.,

Measurement

1. Place the work piece and the gauge appropriately and carry out the measurement of

the job.

2. Prepare a report of the measurement and indicate the characteristics of the work

pieces.


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CALIBRATION OF VERNIER CALIPER:

CHARACTERISTICS OF VERNIER CALIPER:

Parameter Formula used Result

Range -

Span -

Error -

Compensation factor -

Least count

value of 1MSD

no of VSD

Sensitivity

change in O/P

change in I/P

S.NO Slip gauge in

mm

MSD VSD Output value

in mm

Actual value in

mm

Error in

mm

1

2

3

4

5

6

7

8

9

10


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CALIBRATION OF MICROMETER:

S.No Slip Gauge MSD in mm PSD in mm Out put value in mm Error in mm

1

2

3

4

5

6

7

8

9

10

S.no Position of component MSR in mm VSD in DIV VSR in

mm

Output

value in

mm

Actual

vlaue in

mm

1

2

3

4

5

6

7

8

9

10


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CHARACTERISTICS OF MICROMETER:

Parameter Formula used Result

Range

-

Span

-

Error

-

Compensation factor -

Least count Value of 1 PSR

Number of PSD

Sensitivity

Change in O/P

Change in I/P

MEASUREMENTS OF COMPONENT:

Position of

component HSD in mm PSD in mm PSD*LC

Out put

value Actual value mm


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RESULT:

Vernier calliper


Least count :

Sensitivity :

Accuracy :

Micrometer


Least count :

Sensitivity :

Accuracy :


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Ex.No : Date:

MEASUREMENT OF TAPER ANGLE BY USING SINE BAR

AIM

To measure taper angle of given work piece by sine bar.

To set the given sine bar to the given angle.

APPARATUS REQUIRED

1. Sine Bar 2.Slip gauge 3.Workpiece

PROCEDURE

Measurements of Taper Angle

1. Set the work piece to measure the taper angle using sine bar and dial gauge.

2. Transverse the dial gauge plunger over the ramp of work piece.

3. Note down the initial reading, final reading and the length of the traverse.

4. Alternately, try to king the inclined surface of the work piece ,whose taper angle is to

be measure ,to the horizontal plane by placing suitable combination of slip gauge

under the lower end of the work piece.

5. Note down the length of the slip gauge.

6. Calculate the taper angle through the formula given.

Setting the given sine bar to the given angle

Take note of the given angle for which the top surface of the sine bar is to be set.

1. Theoretically calculate the height of the slip gauge required to lift one end of sine bar

Such that top surface of the sine bar make the required slope.

2. Insert the selected combination of slip gauge under one end of the sine bar.

3. Use dial gauge with stand and traverse the plunger of the dial gauge over a know length

and check the slope of the sine bar.


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SINE BAR DIGRAM

MEASUREMENT OF GIVEN TAPER ANGLE USING SINE BAR:

MODEL CALCULATION:

=

S.No Length of sine bar

(mm)

Height of Slip Gauge

(mm)

Difference in

Height

(mm)

Angle


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USING DIAL GAUGE:

S.NO Length of bar

(mm)

Height obtained (mm)

(mm)

Angle in deg

RESULT:

1. The angle measurement is.........

2. Also sensitivity of sine bar .............................degree have been carried out


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Ex.No : Date:

CALIBRATION OF GEAR TOOTH VERNIER AND MEASUREMENT OF GEAR

TOOTH THICKNESS BY GEAR TOOTH VERNIER CALIPER

AIM

To calibrate the gear tooth vernier and to measure the thickness of gear tooth.

APPRATUS REQUIRED

Gear tooth vernier and slip gauge.

PROCEDURE

Calibration

1. Note down the range of the vernier scale in X and Y axis.

2. Select suitable slip gauges and calibrate X and Y axis independently.

3. Produce a calibration report and draw necessary graph.

4. Note down the error in the instrument if any.

Measurement

1. Calibrate the instrument using slip gauge.

2. Find outside diameter of given gear using vernier calliper and count number of tooth in

gear.

3. Calculate pitch scale circle diameter of given gear using formula

Pitch diameter = N*OD/ (N+2) mm

Where,

OD = outer diameter of gear.

N = number of teeth

Module (m) = D/N mm

Addendum = (Nm/2) [1+ (2/N)-cos (90/N)]


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4. Find out tooth thickness in mm

Tooth thickness = N*m *sin (90/N)mm

5. Set variable side of calculated addendum of job place side on top gear tooth to be

measured.

6. Repeat it for variable tooth and find average tooth thickness of given gear.

7. Thickness of the tooth = 2.70mm

CALIBRATION OF THE GEAR TOOTH VERNIER :

Sno

Axis

STD

Input

in mm

Output value in mm Average

output in

mm

Error in

mm I II II

1

X

2

3

4

5

Y

6

7

8


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CHARATERISCTICS OF GEAR TOOTH VERNIER:

Parameter Formula Result

Range -

Span -

Least count Distance moved

(no. of PSD)

Sensitivity Change in output

Change in input

Model Graph:


Tooth No MSR in mm VSR in mm OR in mm CR in mm

E

R

R

O

R

INPUT

O

U

P

U

T

INPUT


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OBSERVATION:

Number of teeth on gear=

Outer diameter=

CALCULATION:

RESULT:

Thus the thickness of tooth was found out and compared with practical value.


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Ex.No : Date:

FLATNESS AND STRAIGHTNESS CHECKING USING AUTOCOLLIMATOR

AIM

To check the flatness and straightness of the given component using autocollimator.

APPARATUS REQUIRED

1) Auto collimator

2) Work piece /object to be tested

DESCRIPTION

An optical system of an auto collimator consists of a light source, condensers, semi-

reflectors, target wire, collimating lens and reflector apart from microscope eyepiece. A

target wire takes place of the light source into the focal plane of the collimator lenses. Both

the target wire and the reflected image are seen through a microscope eyepiece.

The eyepiece incorporates a scale graduated in 0.05mm interval and a pair of parallel

setting wires which can be adjusted. Movements of wires are effected through a micrometer,

one rotation of the drum equals to one scale division movement of the wires.

The instrument is designed to be rotated through 90 degrees about its longitudinal axis

so that the angles in both horizontal & vertical planes are measured.


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PROCEDURE:

1) Keep the auto collimator on the reference surface.

2) Place the reflector on the surface to be tested, such that the reflected beam of light

goes back to the collimating lens.

3) The position of auto collimator is adjusted until the two target wires set in focal plane

of instrument are each covered.

4) Any horizontal tilt in the surface under test leads to vertical target wire to move to the

right.

5) The angular tilt 20 of the reflector is obtained by taking into account the distance (d)

between wires.

d=2Fd

Where, F=Focal length of collimating lens.

TABULATION:

Mirror distance

(mm)

Micrometer reading(mm) Average(mm)

Angle

Tan=y/x A B C


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RESULT:

The values are analyzed and necessary modification of the surface may be

recommended based on the accuracy required on flatness. If the values observed from the

micrometer are varying linearly then straightness/flatness can be judged.


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Ex.No : Date:

MEASUREMENT OF THE VARIOUS DIMENSIONS BY USING

ELECTRONIC COMPARATOR

AIM

To compare the dimensions of given work pieces with length standards using an

Electronic comparator.

APPARATUS REQUIRED

Electronic comparator, slip gauge set and work pieces

DESCRIPTION

The Electronic comparator consists of LVDT (Linear Variable Differential

Transformer) as transducer fitted on a stand. The position of the LVDT can be changed. The

LVDT provides an a.c. voltage output proportional to relative displacement of transformer

core to the windings. The LVDT has three coils; the center or primary coil(P1) is energized

from the external a.c. source. The two secondary identical coils(S1,S2) which are connected

together in phase opposite as shown in fig.

The output amplitude and phase depends on the relative coupling between the two pick

up coils and power coils. There should be a core position for which the voltage induced in


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each pickup coil will be of same magnitude, and the resulting output will be zero. The linear

range of LVDT is primarily dependent on the length of the secondary coils.

PROCEDURE:

1. First the system is switched on and the slip gauge (size equal to the design

dimension of the parameter being checked) is placed between the worktable and

the sensor of LVDT. The table height is adjusted so that the display unit shows

zero.

2. Then the slip gauge is removed and the work-pieces manufactured for the set

design dimensions are inserted between the table and the sensor of LVDT one by

one.

3. The display unit displays the deviation(microns) of the work piece dimension from

the standard value.

4. The jobs whose deviations are within the specification limits (customer specified)

are accepted and the rest are rejected (scrap or rework).

TABULATION

Setting.no Slip gauge

size(mm)

Indicated diff in microns Remarks

lot 1

a)

b)

c)

d)


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Setting.no Slip gauge

size(mm)

Indicated diff in microns Remarks

lot 2 a)

b)

c)

d)

Result:

The scrap and reworks are identified and separated. Only the work-pieces confirming to

the specifications are accepted. This type of separating defectives has found acceptability in

mass production of components


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Ex.No: Date:

CHARACTERISTICS OF FIRST ORDER INSTRUMENT THERMOMETER

AIM

To find the following using thermometers

1) Range of thermometer.

2) The steady state response time.

3) Time constant of the instrument and to draw the time Vs response curves.

APPARATUS REQUIRED

1) Alcohol filled thermometer

2) Mercury filled thermometer

3) Stop watch

DESCRIPTION

Glass thermometer is one of the common type of temperature measuring device .The

envelope comprises of thick walled glass capillary tube ,a spherical wall bulb filled with the

liquid at the bottom and a small bulb at its top end act as safety reservoir. A change in

temperature will cause the liquid to expand or contract in the stem. The raise and fall of liquid

in the capillary against the calibrated scale indicates the temperature of the source.

PROCEDURE:

1) The thermometer bulb is dipped in the water at high temperature (temperature source).

2) Thermometer readings are noted for every equal interval of time until we get steady state

reading.

3) Then the above procedure is repeated with ice water as the temperature source and

thermometer readings are noted.

4) Graphs are plotted between time and response.

5) Time to get 63.3% response is found out.

6) The horizontal line in the plot indicates the steady state condition.


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VERIFICATION OF THE THEORETICAL RESPONSE WITH THE EXPERIMENTAL

VALUES:

HOT WATER SOURCE:

O = i (-t/)

Theoretical Response after 10 sec =

Experimental value after 10 sec =

COLD WATER SOURCE:

O =i (-t/)

Theoretical Response after 10 sec =

Experimental value after 10 sec =

TABULATION:

ALCOHOL THERMOMETER

(A) COLD WATER

S.NO TEMPERATURE(C) TIME

(SEC)


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(B) HOT WATER


(SEC)

1) MERCURY THERMOMETER

(A) COLD WATER


(SEC)


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(B) HOT WATER


(SEC)

Model Graph

RESULT:

Thus the experiment is conducted in liquid thermometer, the variation of time with

temperature is noted and graph is plotted and time constant was found.


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Ex.No: Date:

MEASUREMENT OF FORCE USING A PROVING RING

AIM:

To understand the elastic transducers and measure the force applied on a proven ring.

APPARATUS REQUIRED:

1) Proving ring

2) Displacement measuring and indicating device-dial gauge

DESCRIPTION:

A proving ring is a ring of known physical dimensions and mechanical properties.

When an external compressive or tensile load is applied to lugs or external bosses, the ring

change its diameter, the change being proportional to the applied force. The amount of ring

deflection is measured by means of a highly sensitive displacement measuring device. A dial

gauge/electrical strain gauge system may be used as a secondary transducer.

PROCEDURE:

1) Clamp the proving ring rigidly.

2) Ensure the secondary displacement transducer is properly aligned.

3) The axis of the dial gauge plunger and the line of forces should coincide.

4) Apply a known force at the top most point of the proving ring.

5) Increase the input force in steps and note down the corresponding reading in the dial

gauge.


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TABULATION

Load in

Kg

Load in g(Defelction in div) Unload in g(Defelction in div) Deflection

for Loading

in mm

Deflection

for

unloading

in mm

I II III I II III


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MODEL GRAPH:

Range:

Least Count :

Sensitivty : Change in O/P/ Change in I/P

Proving ring sensitvity :

Dial Gauge sensitvity:

Overal Sensityvity :

RESULT:

Thus the instrument behaves linearly and the linearity range depends upon the

material property of the proving ring.


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Ex.No: Date:

POWER MEASUREMENT USING ROPE BRAKE DYNAMOMETER

AIM

To measure the power and torque by conducting a load test on engine and to draw the

characteristic curves

a) Torque vs. load

b) Power vs. load

APPARATUS REQUIRED

1) Tachometer

2) Measuring tape

3) Spring balance

DESCRIPTION

A rope brake dynamometer consists of one or more rope wrapped around the flywheel

of engine and brake drum whose power is to be measured. The ropes are placed evenly across

the width of the drum. The upward rings of ropes are connected to the spring balance on each

side. The rotation of flywheel produces frictional force and ropes are tightened and

consecutively a force is exerted on the drum. Due to this enormous amount of heat is

produced. The heat is removed using water as coolant.

PROCEDURE:

1) Check the fuel supply to engine, lubrication oil level in the oil pump, water circulation

in the cooling system, etc.

2) Start the engine and ensure no load condition on the brake drum.

3) Allow the engine to stabilize before loading.

4) Now the load is applied gradually on the rope brake dynamometer.

5) For every increase in load, the speed is measured using tachometer.

6) Repeat the procedure for various load and power is measured.

7) Calculate the torque and power using the given formulae.


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SAMPLE DATA:

1) Speed, N = 1500 rpm

2) Radius of the brake drum, R = 0.2 m

3) Theoretical power applied = 1.5 kW

4) Theoretical torque = P*60/(2*pi*N) N-m

5) Actual Torque= W * 9.81 * R N-m

RESULT:

Thus the torque and power measurement is done using rope brake dynamometer.


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Ex.No: Date:

CALIBRATION AND DRAW THE PROFILE BY USING PROFILE PROJECTOR

AIM

1) To calibrate profile projector.

2) To check the dimensions of small size components using a profile projector.

3) To draw the profile of the given job.

APPARATUS REQUIRED

1) Profile Projector

2) Small Screws/Small Gears

DESCRIPTION

The profile projector is basically an optical instrument/comparator which makes use

of the enlarged image principle. The purpose of optical projector is to compare the shape or

profile of a relatively small engineering component with an accurate standard or drawing. It

throws an enlarged image of the component onto a screen. The magnification of the system

will be equal to the size of the object image in screen divided by size of the component. The

available magnified are 10x, 20x & 50x.

CALIBRATION PROCEDURE:

1) The least count of the micrometer in the profile projector is noted down.

2) A standard input (slip gauge) is projected onto the screen and the screen reading is

noted.

3) The error is calculated from the standard input & the output readings are calculated.

4) Then while taking the reading of job, the error is suitably compensated.


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CALIBRATION:

S.NO. Std Input

(mm)

Micrometer Readings Template Reading

Remarks Initial

(mm)

Final

(mm)

Net

(mm)

Screen

Reading

Actual

reading(S.R/

M.F)

CALIBRATION REPORT OF PROFILE PROJECTOR:

Characteristics Quality

Sensitivity

Least count at template

Error

Magnification factor


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MEASUREMENT PROCEDURE:

1) Initially clean the work piece and the table.

2) The fan is switched on and the episcope is turned on.

3) The height of the table is adjustable, so that the clear image of the work piece is seen

on the screen.

4) Then using the micrometer provided for X-direction & other one for Y-direction,

image of the object could be positioned & matched with a template location on the

screen. The worktable is moved with a template location on the screen. The worktable

is moved with the help of micrometer. The readings of the micrometer & that of the

screen are noted.

5) Then by imposing a graph sheet on the screen the profile is plotted for further

reference.

TABULATION:

S.NO.

Parameter

under Test

Micrometer

Readings(mm) Template Reading(mm)

Remarks Initial

Final

Net

Screen

Reading M.F

Actual

reading(S.R/

M.F)

RESULT

Thus, the profile projector is calibrated & the various parameters of a given watch

stud are measured.


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Ex.No: Date:

ANGLE MEASUREMENT USING BEVEL PROTRACTOR

AIM:

To measure the angle of the given work-piece using Bevel protractor.

.APPARATUS REQUIRED:

Bevel protractor work-piece. Rollers and pins shafts

DESCRIPTION:

The equipment consists of a vernier protractor with a movable measuring blade and a

reference blade. The blades are adjustable for both angle and length and are readily applied to

a variety of measuring applications.

The main scale is graduated in degrees of arc. The vernier scale has 12 divisions

each side of the centre zero. These are marked 0-60 minutes of arc, so that each division

equals 1/12 of 60,that is 5 minutes of arc. These 12 divisions occupy the same space as 23

degrees on the main scale. Therefore each division of the vernier is equal to 1/12 of 23 or 1

11/12. Since 2 divisions on the main scale equals 2 degrees of arc, the difference between 2

divisions on the main scale and one division on the vernier scale is 2- 1 11/12 = 1/12= 5

minutes of arc. The accuracy of measurement will largely depend upon the skill of the user.

PROCEDURE:

ANGLE MEASUREMENT USING BEVEL PROTRACTOR:

1. The given work piece is cleaned before taking measurement.

2. The fixed blade of the bevel protractor is made to coincide with the reference

surface of work piece.

3. Move the movable blade of protractor to coincide with outer surface.

4. The angle between the blade is taken from protractor main scale and vernier scale

reading.


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Checking of angle between centre lines of holes:

1. A pin, which must be of good fit, is inserted in each hole (for which the angular

spacing is to checked) and rollers are placed in positions as shown.

2. The dimension M over the rollers is measured and from this, together with the

diameters of the pins ,rollers and shaft,the angle can be measured.

Referring to fig.

M d

Sin = ---------------

D + d

P + d

Sin = ---------------

D+ d

= 2(-)

Where,

M- Distance between the outer edges of the Rollers

P- Diameter of the Pins

d- Diameter of the Rollers

D- Diameter of the Shaft


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TABULATION:

ANGLE MEASUREMENT USING BEVEL PROTRACTOR:

WORKPIECE NAME OF

ANGLE

DESIGN VALUE

IN DEGREES

OBTAINED

VALUE IN DEGREES

DIFFERENCE IN

DEGREES

I a)

b)

c)

d)

II a)

b)

c)

d)

III a)

b)

c)

d)


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CHECKING OF ANGLE BETWEEN CENTRE LINES OF HOLES:

S.NO Diameter of the

Pins (P)

Diameter of the

Rollers(d)

Diameter of the

Shaft(D)

Distance between the outer edges

of the Rollers(M)

RESULT:

Thus using the bevel protractor, all the angles of the given-machined plate are found out

and compared with design values and errors are noted.

And the angle between the centre lines of holes is measured.


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Ex.No: Date:

HYSTERISIS CURVE OF A CANTILEVER BEAM

AIM

To draw the hysteresis curve of a wooden cantilever beam using a dial gauge setup.

PPARATUS REQUIRED

1. wooden cantilever beam

2. dial gauge

3. weights

DESCRIPTION:

The arrangement consists of a wooden beam of length 1metres with a loading

arrangement at its free end. The cantilever beam setup is kept on a reference surface. A dial

gauge with stands is used to measure the deflection of the beam.

PROCEDURE:

1. A wooden cantilever beam is loaded at its free end and a dial gauge which is also kept

on a reference surface measure the deflection of length of beam

2. The indicated readings of the dial gauge are noted down

3. After noting down the deflection for the applied load the load is increased in steps of

50 grams.

4. The Load is decereased in step of 50gms and the reading are noted down

5. The above procedure is repeated by keeping the dial gauge at different sections of the

beam

6. From the readings, a graph between load and deflection is ploted.

Least count = 1/100 = 0.01mm

Cantilever sensitivity =

Dial gauge sensitivity =

Overall sensitivity =


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Load in

gms

Deflection for loading in mm Deflection for unloading in mm

Section-I Section-II Section-I Section-II

1 2 1 2 1 2 1 2

Model Graph:

Result :

From the graph the hysteresis of the give wooden cantilever beam


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Ex.No: Date:

MEASURING CYLINDER AND CONE DIMENSIONS COORDINATE

MEASURING MACHINE

AIM:

To study the functions of different parts of CMM.

To study the conventions used for Machine Coordinate System and Work piece

Coordinate System.

To calibrate the probe tip at three different angles.

To check different dimensional attributes like circularity, cylindricity, flatness, run out,

etc and the corresponding tolerance values

APPARATUS REQUIRED

1.CMM unit

2.Job

DESCRIPTION & PRINCIPLE OF MEASUREMENT:

Co-ordinate Measuring Machine with its parts


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It is used for geometrical feature measurement. The typical "bridge" CMM is

composed of three axes, X, Y and Z. These axes are orthogonal to each other in a typical

three dimensional coordinate system. Each axis has a scale system or encoder that indicates

the translation of the axes. The machine will read the input points from the touch probe by

touching the required location, as directed by the operator or programmer. The machine then

uses the X,Y,Z coordinates of each of these points to determine size and position of the job.

Then the measurands (e.g. length, diameter, angle, flatness, straightness etc.) can be

determined by those points. A coordinate measuring machine (CMM) is also a device used in

manufacturing and assembly processes to test a part or assembly against the design intent. By

precisely recording the X, Y, and Z coordinates of the target, points are generated which can

then be analyzed via regression algorithms for the construction of features. These points are

collected by using a probe that is positioned manually by an operator CMMs can be

programmed to repeatedly measure identical parts; thus a CMM is a specialized form of

industrial robot. In CMM there are mainly two major parts. There are structural system and

probing system. Machine structure, bridge, bearings for moving the bridge, granit table to

support the work piece, vibration isolation system and are included in the structural systems.

Air bearings are the chosen method for ensuring friction free travel. Compressed air is forced

through a series of very small holes in a flat bearing surface to provide a smooth but

controlled air cushion on which the CMM can move in a frictionless manner. In probing

system one touch trigger probe is attached to the Z-axis quill of the bridge. When probe is

rotated about X-axis it is then called as angle A, and when the probe is rotated about Z-axis, then

it is called as angle B.

PROCEDURE:

Job : Artefact supplied by TESA

1. Define plane, line and origin in manual mode.

2. Measure:

(a)Hole diameter, circularity of the Hole and Height,

(b) Cone angle and Diameter of the Cone

(c)Round slot

(d) Measurement of all the holes in polar array in manual mode

(e) Probe calibration is important while creating a new Part Program


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FEATURE DIMENSION 1 2 3 AVG VALUE

mm

Cylinder Diameter

Circularity

Cone

Height

Diameter

Cone angle

Sphere Diameter

REPORT SHOULD CONTAIN:

a. A neat sketch of CMM with proper mentioning of the machine and probe axes.

b. Calibration procedure of probe tip at angles: A__B__, A__B__ and A__B__ and show results.

c. Comment on variation of the standard deviation errors (if any) in previous results.

d. Check dimensional attributes and tolerances for the job provided.

e. Comment on why a sphere has been chosen for the tip.

f. What is the material for probe tip and why is it chosen?

g. Why is it better to use a bigger diameter tip for measurement?

h. What is the principle of slide-guide mechanism for all the three machine axes?

PRECAUTIONS:

! Never touch the granite base on the machine for accuracy issues.

! Do not touch the Axis slides, probe head/tip, and the guides.

metrology and measurements lab.pdf

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