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MECHANICAL MEASUREMENT AND METROLOGY

S.P.B.PATEL ENGINEERING COLLEGE

SAFFRONY INSTITUTE OF TECHNOLOGY

S.P.B.PATEL ENGINEERING COLLEGE(Approved by AICTE and Affiliated to Gujarat University & Gujarat Technological University)

DEPARTMENT OF MECHANICAL ENGINEERING

Laboratory Manual

MECHANICAL MEASUREMENT AND METROLOGY(2141901)

Student Name ._______________________

Enrollment No._______________________

Year ._______________________________

PREPARED BY:

Prof. KIRAN PATEL

Prof . N.K.PRAJAPATI

Prof . FALGUN PATEL


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CERTIFIC TE

This is to certify that Mr./Ms. ____________________

Enroll.no._____________Of B.E 4thSEM MECHANICAL

ENGINEERING in the Year ___________Has satisfactorily

completed theTerm Work in Subject Of MECHANICAL

MEASUREMENT & METROLOGY.

Date of submission:- / / 2016

Incharge Faculty Head of Department


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S.P.B.PATEL ENGINEERING COLLEGE MEHSANA


L BOR TORY PR CTIC L INDEX

SrNo.

Name of Experiment Pageno.

DateofStart

DateofComp.

Comp.Sign

Marks

1Study the static characteristics of

a given measuring instrument.

2

Measurement of various

elements by vernier calipers, Dial

vernier, Digital vernier,Height

gauge.

3

Measurements using outside

micrometers and inside

micrometers.

4 Study and use of slip gauges.

5

Angular measurement by bevel

protector,combination

set,sinebar and angle dekkor.

6

Study and measurement of

roundness,straigtness and

flatness.

7To study about GO and NO-GO

type Plug, Snap and Ring gauges.

8To study about profile projecotor

& Tool makers Microscope.

9To study about surface roughness

measurement.

10

To study about pressure

measurements and Calibration of

pressure gauge with dead weight

pressure gauge.

11

To study about temperature

measurement usingthermocouple and other devices.

12

To study about R.P.M

measurement using Opto-coupler

pick up and Tachometer.


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PRACTICAL NO:-01

TITLE: -Study about static characteristics of measuring instruments.

AIM: - To gain knowledge of terminology related with Metrology.

What is Metrology?

Metrology is the scientific study of measurements. Measurements come in all

forms. Gemstones can be measured for hardness or carat size. Pieces of wood can

be measured for length. Electricity can be measured in amps, volts, and watts.

Mechanical metrology concentrates on standardizing acoustics,

force/pressure, vibration, volume, density, and dimensions. As Asian companies

begin sweeping the country in terms of inexpensive manufacturing, other companies

are relying on mechanical metrology to help them compete. With a set of standards

in place, customers can buy products from any country and know they will be gettingparts with universal measurements. This helps keep repair costs competitive.

As early as the 1950s, businesses worldwide determined that there was a

need to bring unity to measurement in the manufacturing process. As a result, the

International Organization of Legal Metrology was created in 1955. Today, dozens of

countries are members of the organization and share a common goal, to unify

manufacturing and business throughout the world.

With so many countries competing for the market share of manufacturing

business, metrology is essential to keep the market competitive. Having unifiedmeasurements can help with repair costs in the future and ensure that products can

be used worldwide without difficulty. Many organizations hold international

conventions where metrology members can share ideas and concerns, and compare

notes. These metrology conventions are becoming a popular means for unifying the

wide array of measurements used throughout the world.

Over the past decade, there has been an increased need for metrology in

chemistry labs. Metrology of chemistry makes it possible to create strong processes

for quality control of many goods manufactured worldwide. As pollution controls

increase, there is an intense need to regulate worldwide emission controls.

Metrology of chemistry helps ensure that different countries utilize chemicals in a

manner that protects the environment. Chemistry metrology helps define standards

to be used in gas/air mixtures, gas analyzers, inorganic materials, spectrometry, and

microanalysis.

Accuracy: -It is the nearness of the indicated value to the true value of thequantity being measured.

Precision: - It defines the degree of refinement with which a measured value is

stated.
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Threshold: -The smallest measurable input while the resolution defines the smallestmeasurable input change.

Resolution:- When the input is slowly increased from arbitrary(Non-zero) input value, it is observed that the output does not change at all until acertain increment is exceeded; this increment is calledresolution or discriminationof the output.

Sensitivity: -It is the ratio of the change in output signal to a change in inputquantity.

Linearity: - It is the proportionality between input quantity and output signal.

Drift: -It is a slow variation in output signal of a measuring system which is not dueto any change in input quantity.

Dead zone: - Dead zone is caused by backlash and hysteresis in the instrument.

Range: - The difference between the largest and the smallest reading of theinstrument is called the range of an instrument. The Range is expressed by statingthe lower and upper values.

Span: - Span represents the algebraic difference between the upper and lowerrange values of the instrument.

Quiz:

Difference between Accuracy and Precision.

A 0-50V voltmeter has accuracy 2% of f.s.d. what reading will it indicate wheninput voltage is 30V.

Now 2 % accuracy of f.s.d. means 1 V; therefore the voltmeter will indicate either

29V or 31V.. Ans.

The sensitivity of a thermo-couple is 0.03 mill volt per C. for a temperature

difference of 10 C. What will be the difference in its voltage?

A voltmeter has 100 equal divisions, full scale reading 200V. it is possible to

detect 1/10 of a division easily. Find resolution.

Now 1 scale division = 200/100=2V. Resolution = 1/10*2=0.2VAns.

The car speedometer does not indicate any reading below 20 km/hr. The

maximum reading indicate by it is 160 km/hr, find out the range and dead zone of

the meter.

A transducer measures a range of 0-200n force with a resolution of 0.15 percent

full scale. What is the smallest change which can be measured this transducer?.

Determine the resolution of a moving coil voltmeter having a uniform scale with

50 divisions; the full scale reading is 50V and 1/10 of a scale division can be

estimated with a fair degree of certainty.


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Determine the resolution of a digital voltmeter which has read-out range 0 to

9999 counts and its full scale reading is 9.999V.

The calibration range of a certain pyrometer is 300C to 800C. If the dead zone in

it is 0.11 percent of span, determine the temperature which might occur before it

is detected.

OBSERVATION TABLE:

SR. NO. NAME OF INSTRUMENTStatic Characteristics

Range Span L.CZeroerror

1 Vernier calipers 0-200 200 0.02 0.00

2 Vernier Height gauge

3 Vernier depth gauge

4 Out side micrometer

5 Inside micrometer

6 Micrometer depth gauge

CONCLUSION :


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PRACTICAL NO: - 02

AIM:-Measurement of diameters, length and height of various machines parts using(i) Vernier calipers (ii) Dial vernier (iii) Digital vernier calipers (iv) Height gauge

APPARATUS:- Vernier calipers, Dial vernier, Digital vernier, Vernier height gauge,Rectangular MS block, connecting rod, gear etc.

VERNIER CALIPERS:

TERM BRIEF DEFINITION

CaliperA tool that can be used to measure outside dimensions, inside

dimensions, or depths of holes.

Instrument

least count

The size of the smallest division on a scale. For the main scale on

the common vernier caliper this is probably 0.1 cm. With the vernier

scale the least count might be 0.002 cm.

Main Scale

The scale on the larger, fixed portion of the caliper. It gives the

most significant digits in the reading. Make the reading to the nearest

least count of the main scale opposite the zero of the vernier.

Vernierscale

The scale on the smaller sliding portion of the caliper. It gives the

least significant digits in the reading, and sub-divides a mark on the

main scale into 10, 20, or 50 subdivisions. Read the vernier scale at

the point where a vernier line and a main scale line best line up.

Combine the main scale reading with the vernier scale reading to get

a final reading.

CONSTRUCTION:

The vernier caliper consists of two scales:

One is fixed while other is movable. The fixed scale called main scale is calibrated

on L-shaped frame and carries a fixed jaw. The movable scale called vernier scale

slides over the main scale and carries a movable jaw. In addition, an arrangement is

provided to lock the sliding scale on the fixed main scale. For the precise setting of

movable jaw, an adjustment screw is provided.

PROCEDURE:

Before using the instrument, it should be checked for zero error. The zero line on

vernier scale should coincide with zero on the main scale. Then take the reading in

mm on main scale to the left of zero on the main scale.

Now count the number of division on the vernier scale from zero to a line, which

exactly coincides, with any line on main scale. From the figure, we can observe that

the 41stdivision exactly coincides the main scale.

The total reading is now = Main scale reading+


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No. of division that coincides the main scale *

L. C. of Vernier Caliper.

The total reading in mm = 13 + 41 * 0.02

= 13.82 mm.

DIAL VERNIER:


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CONSTRUCTION:

The Dial vernier itself suggests that dial is provided for measurement. Its

construction is same as the vernier calipers. One fixed scale on which movable scale

is provided. According to the movement of vernier scale the dial, indicate the

reading.

DIGITAL VERNIER:

The Vernier Caliper is a precision instrument that can be used to measure internal

and external distances extremely accurately. The example shown below is a digital

vernier caliper as the distances are read from a LCD display.

The most important parts have been labeled. Earlier versions of this type of

measuring instrument had to be read by looking carefully at the imperial or metric

scale and there was a need for very good eyesight in order to read the small sliding

scale. Manually operated vernier calipers can still be bought and remain popular

because they are much cheaper than the digital version. Also, the digital version

requires a small battery whereas the manual version does not need any power

source.

Digital vernier calipers are easier to use as the measurement is clearly displayed and

by pressing the inch/mm button, the distance can be read as metric or imperial.


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PROCEDURE OF MEASUREMENT:

The display is turned on with the on/off button. The external jaws should then be

brought together until they touch and the zero buttons should be pressed. The

vernier caliper can then be used to measure distances. Always go through this

procedure when turning on the display for the first time.

Measuring External Distances:

The material to be measured is placed between the external jaws and they are

carefully brought together. The locking screw is tightened so that the jaws do notmove apart. The digital display can then be read. The distance can be read by in

metric and imperial by pressing the inch/mm button.

Measuring internal distance:


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The example below shows a vernier calipers being used to measure the internal

diameter of a piece of copper tube. The internal jaws are adjusted carefully until they

touch the internal sides. The locking screw is tightened so that an accurate

measurement can be made even if the jaws are knocked against the sides as the

jaws are removed from the hole. The measurement is shown on the LCD display.

Measuring Depth:

Measuring the depth of a hole can be very difficult. However, using a vernier caliper

makes this task easy. The base of the vernier caliper rests on the top of the hole and

the depth-measuring blade is adjusted until it touches the bottom of the hole. The

locking screw is tightened and the measurement can be read on the LCD display.

VERNIER HEIGHT GAUGE:

CONSTRUCTION:

A finely ground and lapped base, the base is massive and robust in construction to

ensure rigidity and stability. A vertically graduated beam or column supported on a

massive base. Attached beam is a sliding vernier and head the vernier scale and a


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FIG:-VERNIER HEIGHT GAUGE

clamping screw. The auxiliary head, which is also calculated to the beam above

sliding vernier head. A measuring jaw or scriber attached to the front of sliding

vernier. Procedure for vernier height gauge: It is same as vernier caliper but the

vernier height gauge is measured height from the reference.

PRECAUTIONS:

First clean vernier caliper by wiping of oil, dust, grit etc.

Clean the two jaws with clean piece of papers.

Set the zero reading of the instrument to be the measure between two jaws.

While measuring dimensions of vernier caliper, it must move carefully.

Hold the past whose dimension is to measure between two jaws.


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OBSERVATION TABLE:

Sr.No

MeasuredPart name

Instrument Dimension

Actual Measurement Avg.

Mainscale

Varnierscale

L.C X mm

QUIZ:-

1. Give a list of possible errors in vernier instruments?

2. Define least count of vernier instruments? How is it determined? Explain

3. Explain the construction and use of the following:

Vernier height gauge

Vernier depth gauge

CONCLUSION:-


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PRACTICAL NO: - 03

AIM: - Measurement of diameters and length of various machine parts using outside

micrometers and inside micrometer.

APPARATUS: -

Outside micrometer [0-25mm]

Outside micrometer [25-50mm]

Inside micrometer [0-25mm]

Inside micrometer [25-50mm]

Screw thread micrometer

Various machined parts.

THEORY: -

INTRODUCTION: -

It is one of the most common & most popular forms of measuring instrument for

precise measurement with 0.01 mmaccuracy. In addition, micrometer screw gauges

are available with 0.001 mmaccuracy.

It classify as:-

Outside micrometer

Inside micrometer

Screw thread micrometer

Depth gauge micrometer.

PRINCIPLE OF MICROMETER: -

The micrometer works on the principle of screw & nut. We know that when screw

is turned through one revolution it advances by one pitch distance i.e. one

revolution of screw corresponds to a linear movement of a distance equal to pitch of

the thread.

COMPONENTS AND THEIR FUNCTIONS: -

U-SHAPED STEEL FRAME: -The outside micrometer has U shaped & C

shaped frame. It holds all the micrometer parts together. It is made of

steel C.I.

ANVIL AND SPINDLE: - The micrometer has fixed anvil protruding 3mm

from the left hand side of frame. Its diameter is same as spindle.


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LOCK NUT: -The Lock provides on the micrometer spindle to lock. Whenmicrometer is at correct, the Lock nut provides the tight holding of job aswell as reading.

SLEEVE AND BASSEL: -The sleeve divided accurately and markedcorrectly in 0.5mm division along the length, which serves as a mainscale.

THIMBLE: -Thethimblecan move over the parallel. It has 50 equal divisions

around its circumference each division has a value of 0.01mm.

RATCHET: -It provides on the end of the thimble. It used to assure accurate

measurement & to prevent too much pressure applied to microscope.

THE OUTSIDE MICROMETER

The micrometer is a precision measuring instrument, used by engineers. Each

revolution of the rachet moves the spindle face 0.5mm towards the anvil face. The

object to be measured is placed between the anvil face and the spindle face. The

rachet is turned clockwise until the object is trapped between these two surfaces

and the rachet makes a clicking noise. This means that the rachet can not be

tightened any more and the measurement can be read.

Fig. Outside Micrometer

EXAMPLE MEASURE READINGS

Using the first example seen below:

1. Read the scale on the sleeve. The example clearly shows 12 mm divisions.

2. Still reading the scale on the sleeve, a further mm (0.5) measurement can be

seen on the bottom half of the scale. The measurement now reads 12.5mm.


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3. Finally, the thimble scale shows 16 full divisions (these are hundredths of a

mm).The final measurement is 12.5mm + 0.16mm = 12.66

INSIDE MICROMETER

The inside micrometer, as the name implies, isused for measuring insidedimensions, such as pumpcasing wearing rings, cylinders, bearings, and bushings.

Inside micrometers usually come in a set thatincludes a micrometer head, various

length spindles(or extension rods) that are interchangeable, and aspacing collar that

is 0.500 inch in length. The spindles (or extension rods) usually graduate in 1-

inchincrements of range; for example, 1 to 2 inch, 2 to 3inch (fig.).

The 0.500 spacing piece is used between the spindle and the micrometer head so

the range of the micrometer can be extended. A knurled extension handleis usually

furnished for obtaining measurements inhard-to-reach locations.


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To read the inside micrometer, read the micrometer head exactly as you would an

outside micrometer,then add the micrometer reading to the rod length(including

spacing collar, when installed) to obtainthe total measurement.

When the 1- to 2-inch spindle is used, and thesleeve and thimble scales are

set to 0.00 inch, thedistance between the face of the anvil and the face ofthe

spindle is exactly 1.00 inch.

SCREW THREAD MICROMETER

Screw thread micrometers measure the pitch of the thread directly. The screw thread

micrometer has a 60-degree pointed spindle and a double V-shaped swiveling anvil

(Figure).

Fig.3.4. Screw Thread Micrometer


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The screw thread micrometer reading indicates the pitch diameter of the thread.

When the micrometer is set at zero, the pitch line of the spindle and anvil coincide

(Figure). When the micrometer is measuring the thread it is measuring along the

pitch diameter of the thread (Figure).

Fig. The pitch line indicates the imaginary thread profile engagement.

Fixed anvil screw thread micrometers are those types of screw thread micrometers

that can only measure thread pitches within a limited range. It is important to make

sure that the screw thread micrometer that you will be using falls within the screw

pitch range of a particular thread. With fixed anvil screw thread micrometers, seven

micrometers will be needed to cover threads from 3 to 64 threads per inch.

Fig. Set of interchangeableanvils for an interchangeableanvil screw thread micrometer

Fig. The pitch diameter of the threadis the most important dimension


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The type of screw thread micrometer shown in Figure has interchangeable anvils to

cover a wide range of thread pitches. Whenever you change the anvils on the thread

pitch micrometer, check the micrometer for accuracy.

Fig. 12 inch screw thread micrometer with interchangeable anvils

THE DEPTH GAUGE MICROMETER

The depth gauge micrometer is a precision measuring instrument, used by engineers

to measure depths. Each revolution of the rachet moves the spindle face 0.5mm

towards the bottom of the blind hole. The diagram below shows how the depth

gauge is used. The ratchet is turned clockwise until the spindle face touches the

Fig. Depth gauge Micrometer

Bottom of the blind hole. The scales are read in exactly the same way as the scales

of a normal micrometer (see previous information sheets).


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PROCEDURE OF MEASUREMENT WITH MICROMETER: -

Before a micrometer used to measure the dimension of a component, it is

necessary to set zero.

After setting the zero, again open the touched anvils and put the job between the

anvils & take reading.

First, of all take the main scale reading & then take Vernier scale reading. Nowadd the reading of Vernier scale multiplying with the least count value to main

value. This is the accurate & final reading.

PRECAUTION IN USING THE MICROMETER: -

First, clean the micrometer by wiping of oil, dirt, dust etc.

Clean measuring face of anvil & spindle with clean piece of paper.

Set the zero reading of instrument.

While measuring dimensions of circular parts the micrometer must moved

carefully over representative area to note maximum dimension only.

OBSERVATION TABLE: -

Sr.No

MeasuredPart name

InstrumentCharacteristic

Dimension

ActualMeasurement

Avg.

X1mm

X2mm

X3mm

Xmm


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QUIZ:-

1. State the principle of a micrometer.Sketch a outside micrometer and Name its

various parts.

2. State the precautions to be taken while using a micrometer?

3. Describe the procedure for checking

Zero error Flatness

Parallelism of a micrometer

4. State the possible sources of error in micrometers.

5. Name any four types of outside micrometers and state their specific uses.

CONCLUSION:-


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PRACTICAL NO: - 04

AIM:- Study and use of slip gauge.

OBJECTIVES:After completing this experiment, the student should be able to know

various uses of slip gauges acquire skill in wringing of gauge blocks

and know the procedure of selection of slip gauges for a particular

dimension.

INSTRUMENTS/MATERIALS REQUIRED:

(1) Set of slip gauges

(2) Surface plate(3) Magnetic base holder

(4) Steel foot rule

INTRODUCTION:

A set of slip gauges consists of a number of rectangular steel blocks suitably

hardened with ground and lapped working faces. They are used conveniently for

building up lengths by combination of number of blocks. The measuring faces of the

two combined gauges adhere together which is known as wringing . Gauge blocks

are meant to be used as reference slandered and direct linear dimensions ofindustrial components. They are classified according to their accuracy viz. C, B,A,

AA grades. The different sets are available for use.

PRECAUTIONS:

(1) Protect slip gauges from dust & dirt.

(2) Keep slip gauges always closed when not in use.

(3) Remove protective coating with petrol and wipe with clean soft linen cloth before

use.

(4) Do not touch lapped faces of gauge blocks.(5) Avoid unnecessary handling of slip gauges.

(6) Immediately after use each gauge block should be wiped clean and replace them

in proper place witch coating of petroleum jelly.

(7) Use slip gauge accessories for marking out tools, measuring plug and ring

gauges inspection of gauges and precision instruments.

(8) Never drop slip gauges.

(9) Never strike slip gauges with other metallic objects.

PROCEDURE:

(1) Take all precautions for gauge blocks before, during and after use.


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(2) For building up required height, wring the smaller number of slip gauges.

(3) For wringing the two gauge blocks, first bring them in contact in right angles to

one another and then turn them through 90.

(4) For the required dimension s(height /length) use the largest possible block in

each step to reduce the number of blocks used to minimum.

ILLUSTRATION:

Build up dimension 48.755mm from standard set of slip gauges.

SOLUTION:

(1)Required dimension is 48.755mm. Use metric set of M112 pieces & 1mm base.

(2)Select the block to eliminate the digit 1.005 i.e 1.005

(3) Select the block to eliminate the digit 0.05 i.e 1.25.

(4) Select the block to eliminate the digit 0.5 i.e 21.50

(5) Select the block to eliminate the digit 25 i.e 25.00

EXERCISE:

Build up the dimension of 58.5835 from the standard set of slip gauges and show

them by figure.


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PRACTICAL NO: - 05

TITLE:Angular measurement Using Combination Set,bevel protector ,Sine bar and

Angle Dekkor.

AIM:a) To measure the angle between two faces of a given component using

combination set and Bevel protractor.

b) To measure the taper angle of a given component using sine bar.

EQUIPMENT AND ACCESSORIES REQUIRED:

1) Bevel protractor with vernier and actual angle attachment (150/300 mm blades),

2) Sine bar (100 mm size), 3) Surface plate, 4) Slip gauges, 5) Dial gauge (0.01 mm

least count), 6) Slotted angle plate, 7) Bolts for locking sine bar to angle plate, 8)

Clamps for locking component to sine bar.

THEORY AND DESCRIPTION:

(A) COMBINATION SET:

The combination square set evolved from the trysquare, small , fixedblade

square. A Combination set consists of a blade and a square head. Size is detrained

by the length of the head. A head may be either plain or hardened and has a clamp

that locks the blade into any position, a spirit level and a scriber. Three measuring

heads are attached to the stainless steel rule, allowing versatile measurement on

various types of work pieces.

(1) Square head: It is used to set the rule at 90 or 45 to an edge of a work pieces.

(2) Center head: it is used to locate centers of round work pieces.

(3) Protractor head: it is used to set the rule at desired angle to an edge of a work

piece. Also it is used for measuring angles.

Procedure:

(1)Attach the square head to the steel rule and check the adjustment at 90and 45

(2) Attach the center head to the steel rule and find the center point of the given joband its radius.

(3) Attach the protractor head to the steel rule and measure the angles in the given

job.


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FIG: COMBINATION SET


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(B)BEVEL PROTRACTOR:

It is the simplest instrument for measuring angle between two faces of component. It

consists of a base plate attached to the main body and an adjustable blade which is

attached to a circular plate called turret containing vernier scale. The adjustable

blade is capable of rotating freely about the centre of the main scale (graduated

around a complete circle from 0to 90, 90to 0and 0to 90, 90to 0) engraved

on the body of the instrument and can be locked in any position. An acute

attachment is provided at the top as shown in fig (1.1) to measure acute angles. The

base of the base plate is made flat so that it could be laid flat upon the work and any

type of angle measured. It is capable of measuring from 0to 360.

The vernier scale has 24 divisions coinciding with 46 main scale divisions (23 oneither side) as shown in fig (1.2). The vernier scale is graduated to the right and left

of zero up to 60 minutes, each of the 12 graduations representing 5 minutes. Since

both the protractor dial and vernier scale have graduations in both directions from

zero, any angle can be measured, but it should be remembered that the vernier must

be read in the same direction from zero as the protractor either left or right. If the

zero graduation on the vernier scale coincides with a protractor graduation, the

number of degrees read between the zeros on the 5 minutes, must be added to the

number of degrees read between the zeros on the protractor dial and vernier scale.

Magnified view of main scale is shown in fig (1.2a).

POCEDURE:

Angle measurement by Bevel protractor:

1. The base plate of the bevel protractor is placed on the top horizontal surface of

the component.

2. Blade locking nut is loosened and by rotating the blade about the centre of the

main scale, the working edge of the blade is made to coincide with the inclinedsurface of the component.

3. Blade is locked in that position by tightening the nut.

4. Vernier scale division coinciding with main scale division is noted.

Inclination of the surface with respect to horizontal is calculated as follows:

Angular reading = (Vernier scale division 5 minutes) + Main scale division in

degrees.


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BEVEL PROTRECTOR:

Observation Table

SRNO Main scale reading( M.S ) Vernier Scale reading( V.S ) Total reading=M.S + ( L.C * V.S )

(C) SINE PRINCIPLE AND SINE BAR:

The Sine principle uses the ratio of two sides of a right angle triangle in deriving a

given angle. The measurement is usually limited to 45from loss of accuracy point of

view. The accuracy with which the sine principle can be put to use is dependent in

practice, on some form of linear measurement. The sine bar in itself is not a

complete measuring instrument. Another datum such as surface plate is needed, as

well as other auxiliary equipment, notably slip gauges, and indicating device to make

measurements. Sine bars used in conjunction with slip gauges constitute a very

good device for the precise measurement of angles. Sine bars are used either to

measure angles very accurately or for locating any work to a given angle within very

close limits.

Sine bars are made from high carbon, high chromium, corrosion resistance steel,

hardened, ground and stabilized. Two cylinders of equal diameter are attached at the

ends.

The axes of these two cylinders are mutually parallel to each other and also parallel

to and at equal distance from the upper surface of the sine bar. The distance

between the axes of the two cylinders is exactly 5 inches or 10 inches in British

System and 100, 200 and 300 mm in metric system.

The various parts are hardened and stabilized before grinding and lapping. All the

working surfaces and the cylindrical surfaces of the rollers are finished to surface

finish of 0.2 m Ra value or better. Depending upon the accuracy of the centre

distance, sine bars are graded as of A grade or B grade of sine bars are guaranteed

accurate up to 0.01 mm/m of length. There are several forms of sine bars, but the

one shown in fig (1.3) is not commonly used. Some holes are drilled in the body ofthe bar to reduce the weight and to facilitate handling.


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The accuracy of sine bar depends on its constructional features:

1) The two rollers must have equal diameter and true cylinders.

2) The rollers must be set parallel to each other and to the upper face.

3) The precise centre distance between the rollers must be known.

4) The upper face must have a high degree of flatness.

USE OF SINE BAR:

a) Measuring known angles or locating any work to a given angle:

For this purpose the surface plate is assumed to be having a perfectly flat surface so

that its surface could be treated as horizontal. One of the cylinders or rollers of sine

bar is placed on the surface plat and other roller is placed on the slip gauges of

height h as shown in fig (1.4). Let the sine bar be set at angle . Then Sin= h/L.

Where, L = Distance between the centre of rollers.

Thus knowing , h can be found out and any work could be set at this angle as the

top face of sine bar is inclined at angle to the surface plat. The use of angle plates

and clamps could also be made in case of heavy components for better results; both

the rollers could also be placed on slip gauges of height h1 and h2respectively. Then

Sine= (h2 - h1)/L

b) Checking of unknown angles:

Many a times, angle of components to be checked is unknown. In such a case, it is

necessary to first find the angle approximately with the help of a bevel protractor. Letthe angle be . Then the sine bar is set at an angle and clamped to an angle plate.

Next, the work is placed on sine bar and clamped to an angle plate as shown in fig

(1.5) and dial indicator is set at one end of the work and moved to the other, and

deviation is noted. Again slip gauges are so adjusted that dial indicator reads zero

across work surface.

If deviation noted by the dial indicator is h over a length of L of work, then height of

slip gauges by which is should be adjusted is equal to hL/L1

POCEDURE:

Angular measurement by sine bar:

1. The sine bar is made to rest on surface plate with rollers contacting the datum

(Surface plat)

2. Place the component on sine bar and lock it in position.

3. Lift one end (roller) of the sine bar and place a pack of slip gauges, underneath

the roller. The height of the slip gauges (h) should be selected such that the top

surface of component is parallel to the datum plate (Surface plat). The parallelism

can be assessed by making the stylus of a dial indicator mounted on a dial gauges


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stand in contact with the upper surface of component and sliding the stylus along the

component surface. If both the surfaces are perfectly parallel, the pointer on the dial

gauges shows the same reading throughout the travel of the dial gauge stylus. If the

surfaces are not parallel then the height of slip gauge back (h) can be altered and

procedure for checking parallelism can be repeated.

Record the final height of slip gauge pack used for achieving parallelism

Calculate inclination = Sine -1(h/L)

PRECAUTIONS:

1. The sine bar should not be used for angle greater than 60because any possible

error in construction is accentuated at this limit.

2. Accuracy of sine bar should be ensured.

3. As far as possible longer sine bar should be used since many errors are reduced

by using longer sine bar.


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OBSERVATION TABLE:

L = ------ mm

SR

NO

Hight

h1

Hight

h2

= sin-1 (h1h2/L )

QUIZ:

1. Differentiate vernier scale and main scale of a Bevel Protractor.

2. How do you measure the angle of a component using Bevel protractor?

3. What is sine principle?

4. How do you measure the angle of a component using sine bar?

5. Which material is used for sine bar?

6. What are the constructional features on which accuracy of sine bar depends?

7. What is the distance between the axes of two cylinders in British system and

metric system?

8. Why are rollers preferred to support the sine bar?

9. Why is a sine bar longer length preferable to the one of a shorter length?

CONCLUSION:


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PRACTICAL NO: - 06

AIM:- Study and measurement of roundness, straightness and flatness.

Objective: After completing this experiment, the student will be able to use dial

gauges for the roundness measurement of a circular bar, measure

straightness of a given job using slip gauge and flatness of a flat

surface using dial indicator.

(A)ROUNDNESS MEASUREMENT:

Equipment/instruments:

(1) Dial gauge

(2) V block

(3) Surface plate

INTRODUCTION:

Roundness can be defined as the radial uniformity of the surface part from its

centerline. There are three main irregularities in the roundness i.e. ovality, lobbing

and no specific form. Error in roundness can be eliminated/reduced by grinding.


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PROCEDURE:

(1) Clean the surface plate, v block and given job.

(2) Divide the circular job into 12 or 8 equal parts with pencil point.

(3) Place the job on the v block and set the dial gauge on the job as shown in fig.

(4) Adjust dial gauge plunger by applying some pressure and then set the gauge to

zero.(5) Now rotate the job and take reading of the dial gauge at point 2 and tabulate the

reading.

(6) Repeat the same procedure for all the remaining points.

STRAIGHTNESS & FLATNESS

EQUIPMENT/MATERIAL:

(1) Straight edge(2) Slip gauge

(3) Surface plate

(4) Dial indicator with magnetic stand

INTRODUCTION:

Guide ways of a lathe spindle of a machine, surface of measuring table and many

other similar situations where if reference surface is not straight or uniformly linear, it

produces defective marketing or product. Hence the straightness is required to be

checked. Naturally, the straightness of a straight edge and surface plate should bevery high, because they are considered as standards compared to other instruments

in laboratory or work shop. The bed or table of a machine should be a perfectly flat

surface. It is required in machine tool that one part sub-assembly is moving or sliding

on another reference surface is not flat, the product produced will be defective. This

will lead to wastage of man power and material. Therefore, it is necessary to check

the flatness of such surfaces.

(B) STRAIGHTNESS MEASUREMENT:

PROCEDURE:

(1) Clean the surface plate and place the job on it.

(2) Mark two point A and B at 0.554L distance on the straight edge and divide them

into two equal parts as shown in figure. Remaining length of the straight edge

should be kept approximately equal on both sides.

(3) Put the straight edge on slip gauge, keep 10 mm slip gauge below A and 20 mm

slip gauge below B.

(4) Insert the required slip gauges below point number 1 of straight edge and note

the reading in table-1.

(5) Repeat the above procedure for point 2 to 9.

(6) Plot the graph of error v/s position.


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(C) FLATNESS MEASUREMENT:

PROCEDURE:

Clean the surface plate and place the job on the surface plate.

(1)

(2) Divide the surface of the flat surface into six blocks by drawing vertical and

horizontal lines on it by soft pencil as shown in figure.

(3) Put the stand on the surface plate after fixing dial indicator in the stand.

(4) Adjust the plunger on point 1 with little pressure.

(5) Adjust the pointer to zero.

(6) Now move the stand and keep the plunger on points 2,3,4,..,12etc. and note

the reading each time. It may be positive or negative.

PRACTICAL NO: - 07

TITLE:-Go and No Go Type Plug, Snap and Ring Gauges.

AIM:- Inspection of diameter using Go and No Go type plug and ring gauges and

thickness using gap or snap gauges.


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GAUGES INTRODUCTION:

Gauges are scale less inspection tool at rigid design, which are used to check the

dimensions of manufactured parts. They also check the form and relative position of

the surface of the parts. They do not determine the actual size or dimension of parts.

They are only used to determine whether the inspected part has been within the

specified limits.

The gauges consist of two sizes corresponding to their max and min limits. For

gauging hole limits plug gauges and for gauging shaft shape gauges are used.

Gauges are easy to employ and can be used in many cases by unskilled operators.

For checking the component with a gauge it is not necessary to make any calculation

and to determine the actual dimensions of the part, the time involved for checking is

considerably reduced. For these reasons in mass production they are used.

PLAIN GAUGES:

They are used for checking holes and shafts. Gauges are classified as:

1. According to their type:

Standard and limit gauges.

Limit gauges.

2. According to their purpose:

Workshop.

Inspection.

Master or reference gauges.

3. According to the form of tested surface: Plug gauges for checking holes.

Snap and ring gauges for checking shafts.

ADVANTAGES OF FIXED GAUGES:

1. They are free from errors due to drift and the original adjustment, non-linear

response, effect of power supply variation and other extraneous factors which

necessitate regular calibration and occasional correction on comparator type

gauges.

2. These provide positive dimensional information.

3. These are portable and independent of power supply avaibility.

4. These involve no other auxiliary equipment and set ups.

5. These can be design to inspect combinations of several dimensioncorresponding

lengths, diameters and angles.

6. These provide uniform reference standards.

7. These are not expensive.


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8. Comparator has to be set form time to time using master fixed gauges.

TYPES OF GAUGES:

STANDARD GAUGES:

If a gauge is made as an exact copy of the mating part of the component to be

checked, it is called standard gauge. It can not be checked to interference fit. It has

limited applications.

LIMIT GAUGES:

They are widely used in industries. As there are two dimensional limits high and low

accordingly they are known as NO and NO-GO gauges.

PLAIN PLUG GAUGES:

Generally the gauging members of plain gauges are made of suitable wearresistance steel and the handle can be made of any suitable steel. They are normally

of double ended type for size up to 63mm and of single ended type for size above

63mm.

The various types of plain plug gauges are shown below:

(1) For size up to 10 mm GO and NO-GO type. (Solid type).

(2) GO and NO-GO type gauges for size over 10 mm and up to 30 mm. (Taper

inserted type).

(3) (a)GO and NO-GO type gauges for size over 30 mm and up to 63 mm.(fig : 3)

(b)GO and NO-GO type gauges for size over 63 mm and up to100 mm.(fig : 3)

(4) GO and NO-GO type gauges for size over 100 mm and up to 250 mm.(fig : 3)

(5) In this type, gauges with the gauging portion integral with the handle are replaced

with renewable end. (Renewable type).

(6) For relatively short through hole. It has both the ends on one side of gauge as

shown in fig. (Progressive type)

(7) To avoid jamming of the plug gauge inside the hole they are used. It is of elliptical

shape and so it touches the hole with major axis end points. The chamber behind

the pilot lifts the gauges into link, making jamming impossible and advantages isthat it can be handle with less care.(Pilot plug gauge).See fig

PLAIN RING GAUGES:


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Plain ring gauges are generally manufactured as individual Go and No-Go rings.

Special ring gauges can be manufactured with both Go and No-Go diameters on a

single ring if requested. Standard plain ring gauges below 65 mm [2.5"] are

manufactured from hardened steel blanks kept in stock and can be delivered within 2

weeks.

The various types of these gauges are as follows:

(1) For fig : 9 dimension d2 varies from 22mm to 112 mm. Correspondingly b varies

from 5mm to 22 mm and c from 0.4mm to n1.6 mm.

(2) For fig : 10 dimension d2 varies from 125 mm to 355 mm. corresponding to

d1=120 mm to 355mm, dimension d2 varies from 100 mm to 280 mm,b1 from 12

mm to 18 mm, c from 2.5 mm to 4 mm, r from 3mm to m6 mm, t from 3 m to 8

mm.

(3) For fig : 11 dimension d2 varies from 22 mm to 112 mm with d1 from 3 mm to

5mm and 66 mm to 709 mm respectively, corresponding b1 varies from 3 mm to

8 mm, c from 0.4 mm to 1.6 mm.

SNAP GAUGES:

Thread and plug gauges Thread and pluggauges

These images illustrate an alternative type of gauge. The snap gauge has four anvils

or jaws, the first one or pair (outermost) are set using the upper limit (tolerance) of

the part and the inner set adjusted to the lower limit of the part.


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The usage of this gauge may be more intuitive than the plug type. A correctly

machined part will pass the first set of jaws and stop at the second end of test. In

this manner a part may be checked in one action, unlike the plug gauge that needs

to be used in the correct sequence and flipped to access the second gauge.

The left image is a plain snap gauge used to measure outside distances (diameters),

the right hand image shows two views of a thread snap gauge. it is very useful onefor mass production

(1) RIB TYPE SNAP GAUGES:

Double type snap gauges can be conveniently used for checking size in the range of

3 to 100 mm and single ended progressive type snap gauges are suitable for range

of 100 mm to 250 mm with gauging surface suitably stabilized, grounded and

lapped.(see fig.)

(2) PLATE SNAP GAUGES :

Double ended type plat snap gauges are used for sizes in the range of 2 mm to 100

mm and single ended progressive size range of 100 mm to 250 mm with gauging

surface properly hardened, stabilized ground and lapped. They are reasonably flat

and all sharp corners and edges are removed.

ADJUSTABLE TYPE GAP GAUGES:

In this gauges gauging anvils are adjustable end wise in the horse shoe frame. They

are set with the help of slip gauges to any particular limit required. It possible tomade gauges within about 0.002 mm of desired size and so their use enable faller

advantages to be taken of manufacturing tolerance. The adjustably also ended GO

anvils to be taken up any time. If anvils faces lose their flatness with use. They can

be reground quite easily. For designing of gap gauges some design consideration.

COMBINED LIMIT GAUGES:

In the case of gauging of cylindrical holes, it is possible to combined both GO and

NO GO dimensions of a plug gauges and thus a single gauge doing the checking of

both lower and upper limit.

POSITION GAUGES:

They are commonly used and designed on based of shape of work. They are used

for checking the position of some feature on the work relative to another reference

point or surface. Fig shows a position gauge for checking recess with respect to

some flat surface and fig shows location of parallel surface to the reference surface

by means of gauge.


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CONTOUR GAUGES:

These are employed for checking the dimensional accuracy and shape of irregular

work. They are made of similar profile as that of work. e.g. radius gauges are

employed for checking the shape of fillets.

MISCELLANEOUS GAUGES:

They are used for not only shaft and hole checking but can be designed for all type

of application for checking purposes in production shop and checking.

RECEIVER GAUGES:

They are designed to simultaneously check a number of features of work pieces.

They are often used for checking components before assembly.

PROFILE GAUGES:

They are used to check the form of the components. Profiles are difficult to be

checked by limit gauges and it is usual practice to use fixed gauges for profile

checking.

GAUGE DESIGN:

To a greater or lesser extend, every gauges is a copy of the part which mates with

the part of which gauges are designed. For example, in the design of bushing gauge

is a copy of opposed part shaft to which bushing is mate.

TAYLORS PRINCIPLE:

According to GOand NO GO gauges should be designed to check maximum and

minimum material limits which are checked as below:

GO LIMIT:

This consideration is applied to that limit of the two limits of a size which corresponds

to the maximum material limit consideration.

NO GO LIMIT:

This consideration is applied to that limit of the two limits of a size which corresponds

to the minimum material limit consideration. i.e. lower limit of shaft and upper limit of

a hole.Fig. Shows GO plug gauges and GO snap gauges.


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IMPORTANT POINTS FOR GAUGE DESIGN:

(1) The form of GO gauges should exactly coincide with the form of opposed parts.

(2) GO gauges are complex gauges which enables several related dimensions to

be checked simultaneously.

(3) In inspection, GO gauges must always be put into conditions of maximum

impossibility.(4) NO GO gauges are gauges for checking a single element of feature.

(5) In inspection, NO GO gauges must always be put into conditions of maximum

possibility.

LIMIT GAUGES:

The various types of limit gauges used for gauging internal diameters of holes are:

(1) FULL FORM CYLINDRICAL PLUG GAUGES:-The gauging surface is in the

form of an external cylinder. Generally a small groove cut near the leading end ofthe gauges and the remaining short cylindrical surface is reduced in order to act as a

pilot. The method of attaching gauges to handle should be such as not to affect the

size and form of gauge by producing undesirable stress.

(2) FULL FORM SPHERICAL PLUG OR DISK GAUGES:- This has gauging surface

in the form of a sphere from which two equal segments are cut off by planes normal

to the axis of the handle.

(3) SEGMENTAL CYLINDRICAL BAR GAUGES:- It has the gauging surface in one

of the following two forms: External cylindrical form from which two axial segmentsare made by lowering down the surface of two planes as shown in fig.

(4) SEGMENTAL SPHERICAL PLUG GAUGES:- It is similar to full form spherical

plug or dick gauge but two equal segments cut off by planes parallel to the axis of

the handle in addition to the segments cut off by planes normal to the axis of handle

as per fig..

(5) SEGMENTAL CYLINDRICAL BAR GAUGE WITH REDUCED MEASURING

FACES:- It is similar to segmental cylindrical bar gauge but has reduced measuring

faces in a plane parallel to the axis of the handle as shown in fig..

(6) ROD WITH SPHERICAL ENDS:- It has spherical surfaces which form part of one

single sphere.

THE STANDARD LIMIT GAUGES USED FOR GAUGING EXTERNAL

DIAMETERS OF SHAFTS ARE:

FULL FORM CYLINDRICAL RING GAUGE:

It has auging surface in the form of an internal cylinder and whose wall is thickenough to avoid deformation under normal condition.


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GAP GAUGES:

It generally has one flat surface and one cylindrical surface the axis of two surfaces

being parallel to the axis of the shaft being checked. The surface contributing the

working size may both be flat or both cylindrical also.

PLUG GAUGES:

Hardened and ground plug gaugeReplaceable thread and plug gauges

These gauges are referred to as plug gauges; they are used in the manner of a plug.

They are generally assembled from standard parts where the gauge portion is

interchangeable with other gauge pieces (obtained from a set of pin type gauge

blocks) and a body that uses the colletprinciple to hold the gauges firmly. To use

this style of gauge, one end is inserted into the part first and depending on the resultof that test, the other end is tried.

In the right hand image, the top gauge is a thread gauge that is screwed into the part

to be tested, the labeled GO end will enter into the part fully; the NOT GO end

should not. The lower image is a plain plug gauge used to check the size of a hole,

the green end is the GO, and red is the NO GO. The tolerance of the part this gauge

checks is 0.30mm where the lower size of the hole is 12.60mm and the upper size is

12.90mm; every size outside this range is out of tolerance. This may be initially

expressed on the parts drawing in a number of styles, three possibilities may be:-

12.75mm +/- 0.15mm

12.60mm +0.30 -0.00

12.90mm +0.00 -0.30

PLAIN:

It is a full form of GO gauge representing a plain or tapped end shank. It is provide

with one ring marked on the gauge plane and another ring to indicate the minimum

depth of internal taper. The dimension of gauging portion represents basic size. The

distance between two ring marks Z correspond to permissible deviation of gauge

plane position for the particular taper. It can test internal taper also.
http://en.wikipedia.org/wiki/Collethttp://en.wikipedia.org/wiki/Collethttp://en.wikipedia.org/wiki/Collet


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TANGED:

It is a full form of GO gauge representing the virtual size of the shank of basic

dimension having tang which is one of the top limit of its thickness and eccentric by

the maximum permissible amount. It is provide with one ring marked on the gaugeplane and another ring to indicate the depth of internal taper.

RING GAUGE:

PLAIN:

This gauge represent on internal taper of basic size. It is used for verifying the taper

of tapped or plain and shank. As the ring gauge is inserted to be used for verification

of internal taper, the dimension of gauging portion represent an internal taper basic

size. For inspecting external taper, the ring gauge is inserted with light pressure at

the extreme position the small end of taper shank under test should lie flush or short

of the face of the ring gauge on the small end.

TANGED:

This gauge represents an internal taper of basic size. A limit step is provided at the

small end of taper which verifies the length of shank form the gauge plane and also

combined effect of tang thickness and its offset. A step is provided to verify, the tang

slot will accept a shank even worst case. For testing, the external taper of the tanged

and shank the ring gauge will insert light pressure.

CONCLUSION:-


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PRACTICAL NO: - 08

TITLE: Profile Projector & Tool Makers Microscope

AIM:- Measurement of Profile using Profile projector and Tool Makers Microscope.

[A] PROFILE PROJECTOR:-

FEATURES:-

1. Medium sized model that features high versatility and easy operation.

2. Digital readout projector for angular measurement.

3. Screen glass carries the chart clips.

4. Easy to read digital XY-coordinate counters located near the projection screen to

minimize eye movement.

5. Floating type table for speedy measurement.

DESIGNATION OF PARTS:-

1. Base /body

2. Image screen

3. Driver for vertical and complete

assembly

4. Lamp casing for diastolic and

episcopic lighting

5. Bulb holder with a wire

6. Tighting screw

7. Condenser lens for diastolic and

epidiascope

8. Objective lenses with socket and

turret9. Objective glass type

10. Micrometer heads and slide

11. Panel board

12. Spindle for V-model

13. Swith for lighting

14. Fuse

15. Regulator for lighting intensity

16. Socket input

17. A & B socket outputs

18. Socket inputs

19. Name plate

20. Vernier scale

21. Episcopic mirror


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SPECIFICATION OF PROFILE PROJECTOR:-

ModelHPP 310

Screen dia.300mm

Work stage350 x 250mm

Travel220 x 110mm

Magnification:

Standard10X 20X

Optional 25X 50X

SPECIFICATION OF HALOGEN PROJECTION LAMP:-

Power - 150 watt

Voltage - 24 volt

Height of filament -32 mm

Socket with two contacts - 10 mmDistant between two contacts - 6.35 mm

Type Philips no. - 7158

Osram type no. - 64640

CENTERINGTHE DIASTOLIC LAMP:-

1. Draw the diagonals accurately with a pencil on a trans paper.

2. Remove the objective and condenser lamp.

3. Switch the regulator to half brilliance.

4. Slacken clamp screw 8 to enable the lamp socket to be moved in direction B-B & C-C.5. Move lamp socket in direction A-A/B-B & C-C until the image of filament is shap &

central on the screen.

6. Tighten the clamp screw and grab screw 39.

7. Mount objective and condenser lens at its position.

SETTING UP THE SURFACE ILLUMINATION:-

1. Mount the required lense.

2. Bring the proper height of light beam.

3. Switch on the light & moves mirrors centrally.4. Replace the piece of paper.

5. The clarity can be improved.

6. Try to get the sharp and clear image.

THE MAGNIFICATION:-

For accurate reading use magnifying glass.

Check can be made with slip gauge arbors of accurate dimension etc by keeping it on

the table and measure the image on the paper.

We accurately set the magnifications, but a result of vibration on which they have beensubjected during transport proportional to travel.


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PROCEDURE:-

Following type of steel screws is used for inspection

First measure the dimension using screw thread micrometer screw.

Then check the dimension using profile projector.

Fig. Threaded Screw

The following parameters were assessed:

1 - Dimensions:

a. body diameter (proximal non-threaded portion);

b. inner diameter;

c. thread fillet height;

d. step length;

e. thread apex lengths;

Fig. Metrologic evaluation of the screw


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[B] TOOL MAKER MICROSCOPE:-

It is based on the principle of optics. The microscope consists of heavy hollow bases;accommodates the illuminating unit underneath & above this, on the surface of thebase, the work table carriage is supported on the balls & controlled by micrometer

screw. Projecting up from the near base is a column which carries the microscope unit & inter

changeable eyepiece.

Light from source lamp reflected as parallel beam by prison at the end of tube so imageis created on the translucent screen. Magnification can be from 10X to 100X.

Linear movement of the table is controlled by micrometer screw having a movement upto accuracy 0.0025mm.

For the most effective manipulation magnified image of the work compared through theeyepiece superimposed on a prepared background engraved on a glass disc on aneyepiece. The operator unit is prepared with radialand cross setting lines. This may be rotated by a

knurled screw for setting any of line with work orimage and reading of the protector may be made to1 minute.

THE CHIEF APPLICATION OF THE TOOL ROOM

MICROSCOPE ARE AS FOLLOWS:

1. The determination of relative position of variouspoints on work.

2. Measurement of angel by using a protectoreyepiece.

3. Comparison of thread forms with master profilesengraved in the eyepiece, measurement of pith andeffective diameter.

SPECIFICATION OF TOOL MAKERS MICROSCOPE:-

Work stage - 150 X 150 mmTravel - 50 X 50 mmMagnification:Standard - 30 X standardOptional - 30 X standard

SPECIFICATION OF HALOGEN LAMP:-

Power - 50 wattVoltage - 12 voltHeight of filament - 12 mmSocket with two contacts - 8 mm


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Distance between two contacts - 4 mmType of G.E. no. - 34718

PREPARING FOR WORK:-

Tool makers microscope requirement is as same as profile projector discussed in[A].

SETTING UP:-

It requires 50cm free space all around and single phase lighting current of 220 volts.

WORK-ROOM REQUIREMENT, CENTERING AND SURFACE ILLUMINATION:-

All the work room requirements, centering of lighting position and surface illuminationtechnique as same as in case of profile projector discussed in section [A].


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PRACTICAL NO: - 9

TITLE:-Surface Roughness Measurement

OBJECTIVE;

1. To measure the surface roughness of the given specimens using roughness tester

2. To show the variation of surface roughness as a function of cutting conditions i.e.,speed, feed, depth of cut and tool geometry etc

MEASURING INSTRUMENTS AND MATERIAL RIQURIED:

1. Surface roughness tester (SJ- 201)

2. Precision roughness specimen, Test specimens, Calibration stage

3. Height gauge, Adapter for the height gauge, support

4. Nose Pieces, Digimatic data processor (DP-1 HS)

TERMINOLOGY AS PER INDIAN STANDARD:

Surface roughness: It concerns all those irregularities which form surface relief and which

are conventionally defined within the area where deviations of form and waviness are

eliminated.

PRIMARY TEXTURE (ROUGHNESS):

It is caused due to the irregularities in the surface roughness which results from the

inherent action of the production process. These are deemed to include transverse feed

marks and the irregularities within them.

SECONDARY TEXTURE (WAVINESS)

It results from factors such as machine or work deflections, vibrations, chatter, heat

treatment or warping strains, waviness is the component of surface roughness upon which

roughness is superimposed.

CENTRE LINE:- The line about which rough is measured.

LAY:-It is the direction of the predominant surface pattern: ordinarily determined by the

method of production used.

TRAVERSING LENGTH:It is the length of the profile necessary for the evaluation of the

surface roughness parameters.

SAMPLING LENGTH (I):Is the length of profile necessary for the evaluation of

irregularities to be taken into account. This is also known as the cut off length as regard

to the measuring instruments. It is measured in a direction parallel to the general direction

of profile.

THEORY:


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Surface texture is deemed to include all those irregularities which, recurring many times

across the surface, tend to form on it a pattern or texture. The irregularities in the surface

texture which result from the inherent action of the production process is called roughness

or primary texture. That component of surface texture upon which roughness is super

imposed is called waviness or secondary texture. This may result from such factors as

machine or work deflections, vibrations, chatter, heat treatment or warping strains. The

direction of the predominant surface pattern, ordinarily determined by the productionmethod used is called lay. The parameters of the surface are conveniently defined with

respect to a straight reference line. The most widely used parameter is the arithmetic

average departure of the

Filtered profile from the mean line. This is known as the CLA (CentreLineAverage) or

Ra (roughness average)

Arithmetic mean deviation of the Profile, Ra

Ra is the arithmetic mean of the absolute values of the profile deviations (Y i ) from the

mean line.N

Ra = 1/N Yi

I=1

Rootmean- square deviation of the Profile, Rq :

Rqis the square root of the arithmetic mean of the squares of profile deviations (Y i ) from

the mean line.

N

1/N Yi2

I=1

Maximum height of the profile, Ry:

Ry is the sum of height Ypof the highest peak from the mean line and depth Yvof the

deepest valley from the mean line.

Ry = Yp + Yv

OUTLINE OF SURF TEST SJ- 201

The surf test -201 is a shop-floor type surface roughness measuring instrument, which

traces the surfaces of various machines parts, calculates their surface roughness based

on roughness standards, and displays the results.


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Surf Test SJ-201 Surface roughness measurement principle:

A pick-up which is usually called as the Stylus attached to the detector unit of the surf

test SJ- 201 will trace the minute irregularities of the work piece surface. The vertical stylus

displacement during the trace is processed and digitally displayed on the liquid crystal

display of the surf test SJ- 201. The measurement principle of surf test SJ- 201 is show in

fig. The instrument consists of the display unit and drive/detector unit is designed to beremovable from the display unit. Depending on the shape of the work piece, it may be

easier to perform measurement without mounting the drive/detector unit to the display unit.

Name of each part on the display unit is shown in fig. The detector in turn can be detached

from the drive unit. Each time a measurement task has been completed with the surf test

SJ-201, it is recommended that the detector be detached from the drive unit and stored in

a safe place.

Fig. Terminology as per Indian Standard


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Fig. Measurement Principle of Surftest SJ-201

LIST OF SURF TEST SJ-201 OPERATION MODE:

The surf test SJ-201 has various operation modes including the measurement mode,calibration mode, condition setting mode, RS-232C communication mode, and detectorretraction mode.

MEASUREMENT MODE:

Starts and stops measurement, calculates and selects measurements parameters to bedisplayed, and performs SPC output.


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CALIBRATION MODE:

Sets the calibration value prior to measurement and performs calibration measurement.

CONDITION SETTING MODE:

Sets and modifies measurement conditions. This mode has 11 sub-modes as shown in

chart.

RS232C COMMUNICATION MODE:

Used for communication with a personal computer.

DETECTOR RETRACTION MODE:

Retracts the detector as required.

Relationship between the operation modes and available keys is shown in Table.

MEASUREMENT OF SURFACE ROUGHNESS:

Surface roughness measurement with the surf test SJ-201 includes

1. Mounting/ dismounting the drive unit/ detector, and cable connection, etc. according to

the feature of the work piece to be measured.

2. Selection of power supply i.e., either the AC adaptor or built-in battery.

3. Modifying the measurement conditions as necessary.

4. Calibrating surf test SJ-201 to adjust the detector gain for correct measurements.

5. Measuring the roughness specimen and display the result.

6. Outputting the measurement data or perform communication with a personal computervia the RS- 232C interface.

PROCEDURE:

MODIFYING MEASUREMENT CONDITIONS:

Table shows the measurement conditions that can be modified by the user. If they are not

modified, then measurement will be performed according to the default values,

measurement conditions are modified according to the surface roughness parameters, the

amplitude of roughness, the conditions of the objective area of measurement, etc.The surf test SJ-201 can obtain each roughness parameter based on the new JIS, old JIS,

DIN ISO and ANSI standards. Evaluation according to any one of the standards may be

obtained from Reference information (Users manual)

CALIBRATION OF MEASURING INSTRUMENT:

The process of calibration involves the measurement of a reference work piece (precision

roughness specimen) and he adjustment of the difference (gain adjustment), if there is any


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Fig. Name of each part on the display Unit

between the measured value and the reference value(precision roughness specimen).

With out properly calibrating the instrument, correct measurements cannot be obtained.

Calibration of surf test SJ- 201 with the supplied precision roughness specimen must be

performed with the default values mentioned in table.

1. Precision roughness specimen and calibration stage are placed on a level table.

2. Surf Test SJ-201 is mounted on the calibration stage.


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3. Surf Test SJ-201 is set so that the detector traversing direction is perpendicular to the

cutter mark of the precision roughness specimen. It should be confirmed that the

detector is parallel to the measured surface as shown in fig.

4. If [CAL/STD/RANGE] key is pressed in the measurement mode, the calibration mode is

entered and current calibration value is displayed. In this stage the calibration value

can be modified, if the displayed value is different from that marked on the precision

roughness specimen.

5. [n/Ent] key is pressed after confirming the displayed value, so that the entered

calibration value is set.

6. [START/STOP] key is pressed to begin the calibration measurement. The symbol is

displayed while the detector is traversing and the measured value will be displayed

when the measurement has been completed.

7. [n/Ent] key is pressed so that the calibration factor is updated, completing the entire

calibration operation.

8. [MODE/ESC] is pressed. This restores the measurement mode and retains the

calibration factor obtained in the previous operation.

ACTUAL MEASUREMENT OF ROUGHNESS SPECIMEN:

Surf Test SJ-201 is placed on the work piece, if the work piece surface is large enough.

For measurement to be successful, it should be performed on a firm base that is insulated

as well as possible from all sources of vibration. If measurement is performed being

subject to significant vibrations, results, may be un reliable.

1. Work piece is poisoned so that the measured surface is level.

2. Surf Test SJ-201 is placed on the work piece, In this operation SJ-201 is supported by

to reference surfaces at the bottom of driving unit. It must be confirmed that the stylus

is in proper contact with the measured surface and the detector is parallel to the

measured surface.

3. [START/STOP] key is pressed in the measurement mode, the detector starts traversing

to perform measurement.

4. After the measurement has been completed, the measured value is displayed on the

LCD.

5. [PARAMETER] key is pressed until the desired parameter value is displayed on the

LCD.

OUTPUTTING MEASUREMENT RESULT:

1. The Surf Test SJ-201 is connected to a Digimatic data processor (DP-1HS) to output

the measurement results (including the unit of measurement) as SPC data.


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2. DP-1HS is turn to ON position.

3. [PARAMETER] key is pressed until the objective parameter for output is displayed.

4. POWER/DATA] key is pressed so that the measurement result will be outputted from

the Surf Test SJ-201 to the DP-1HS.


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PRECAUTIONS:

i) Never touch the stylus, otherwise it may be damaged.

ii) Do not hold the detector when detaching the drive/ detector unit. Otherwise, the

detector may be damaged.

iii) Confirm that the detector is parallel to the measured surface.

iv) Confirm that the stylus is in proper contact with the measured surface.

v) Calibration of SJ-201 with the precision roughness specimen must be performed with

the default values that have been used for calibrating the roughness specimen.

CONCLUSION:-


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PRACTICAL NO: - 10

TITLE:-Pressure Measurement using pressure Transducer and calibration of pressure

gauge with dead weight pressure gauge.

AIM:-Pressure Measurement using pressure Transducer and calibration of pressuregauge with dead weight pressure gauge.

INTRODUCTION OF TEST SET UP:-

The Instrumentation Tutor is meant for measurement of pressure trough Pressure cell. The

Tutor is very useful for study of pressure through pressure Cell. The circuit diagram is

given on the top cover on the tutor to understand the measurement parameter at a glance.

All the different test point are also provided on top cover with giving their heading to

facilitate the student to understand without any operation instruction by any person.

Range

Resolution

Display

Excitation

Analog output

Power source

Top Panel:

1. Display

2. Inputs

3. Cal check

4. Zero pot

5. Span pot

6. ON/OFF switch

7. Fuse

8. Light LED

9. Test point

: 10 kg/cm

: 0.1 kg/cm2

: 3-1/2 digit

: 5.00Volt, DC

: 2Volt, DC

: 230 V +/-10%,50 HZ

: 3-1/20digit

: Pressure cell

: On pushing the red switch you will observe

the adjusted calibration on the display.The

present calibration adjustment is 8.3

: Provided for zero adjustment

: : : Provided for calibration

: To ON/OFF the system

: 0.5 milliamps

: Indicates the power supply when theWhen is in ON position.

a) display card supply +/-5V

There are three terminals

Red :+5V

Green : Common

Black : -5V

b) Pressure cell signal conditioner card supply

+/-12V

There are three terminals forRed : +12V

Green : Common


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Black : -12V

c)Analogue output 2V full range of Pressure cell

Red : High

Green : Low

d) Pressure cell full bridge

When the system is in OFF position the RED and

Green points are for Excitation 350 ohms.

The Yellow and Black pints are for Signal 350 ohms.

When the system is in ON position,

Red : E+

Green : E-

Excitation : 5V fixed

Signals :

Yellows : +

Black : -

Signal maximum pressure 10 kg/cm2 6.6mVs

NOTE-All the test points can be measured through multimeter and/or Cro.

OPERATING PROCEDURE:

1. TO connect the pressure cell at the 9 pin connector.

2. Power ON the switch. The front RED LED glow with which indicates the power available

on the instrument.

3. Give some time to stabilize the instrument for stabilization (warm up time).4. Balancing the pressure Cell by through the corresponding ZERO ten turn timpot.

5. Set the gain of Pressure cell by SPAN ten turntrimpot.

6. Then to push the micro switch to ascertain the reading position of CAL. The present CAL

position in the instrument is 8.3

7. For example :

To apply the pressure on pressure cell say 10 Kg/cm2. You will observe some reading

on the display say something like 9.6 or so. Now you have to adjust this reading say

10.0 by rotating the span pot and to stop rotating with the desired 10.0 counts are

visible.

PRECAUTIONS:

1. To get the good performance from the Tutor you have to maintain room temperature.

2. To check the power source. It should be 230V+/- 10%, 50 HZ. To avoid over voltage

hazards.

3. To get best performance, you have to put the instrument at dust proof and Humidity

free environment.

4. Do not try to open the instrument or repair it. Contact manufacturer in case Of any

fault/difficulty.


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THEORY:

New-tech pressure transducers employ foil type strain gauges bonded to the pressure

sensitive diaphragm. The transducer is a single body piece machined from special steel,

treated for maximum stability.

CONTROL POTS:

- Zero adjust for trimpot

- Span adjust for trimpot

- Excitation : 5Volts DC

- Cal check : _________

OBSERVATION TABLE:

Sr.

No.

Pressure Applied

(in kg/cm2)

Display

(in kg/cm2)

Reading Signal

(in mV)

Output

( in Volts)

No pressure

2

4

6

8

10

CONCLUSION:


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PRACTICAL NO: - 11

TITLE: - Temperature Measurement using Thermocouple.

AIM: To Measure The Temperature Using Thermocouple (Range: Up To 100 C Iron-

Constantan)

.

INTRODUCTION OF TEST SET UP:

The New-Tech temperature calibrator is meant for measurement of temperature

through thermocouple. The calibrator is very useful for study of temperature through

thermocouple sensor. The circuit diagram is given on the top cover on the calibrator to

understand the measurement parameter at a glance. All the different test points are also

provided on the top cover with giving their headings to facilitate the user to understand

without any operation instruction by any third person.

Thermocouple Range

Resolution

Analogue output

Top Panel:

1. Display

2. Inputs

3. Zero pot

4. Span pot

5. ON/OFF switch

6. Fuse

7. Light LED when

8. Test point

: 100

: 0.1

: 2 Volts DC

: 3-1/2 digit LED

: Thermocouple sensor (Iron Constantan)

: Provided for zero adjustment

: Provided for calibration

: To ON/OFF the system

: 0.5 milliamps

: Indicates the power supply it is in ON position.

: a) Display card supply +/- 5V

There are three terminals:

Red : + 5V

Green : Common

Black : -5V

:b)Thermocouple Signal Conditioner

Card supply +/- 5V

There are three terminals for:

Red : +12V

Green : Common

Black : -12V

:c) Analogue output 2V full scale display

Red : +VE

Black : -VE

:d) Sensor input point

When the system is in OFF

you can measure the resistance of sensor


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EQUIPMENTS USED:

1. Thermocouple

2. Thermistor3. Bimetallic temperature gauge

4. Mercury type thermometer

5 .Pyrometer

PRINCIPLE:

The principle on which various temperature measuring devices work is shown below:

(1)Principle of expansion e.g mercury thermometer range:-40to400 c

(2)Principle of Electrical resistance e.g. resistance thermometer range:

-240 to 980c(3)Change of physical state e.g. bimetallic thermometer range: -73to540 c

(4)Change in chemical state e.g. thermistor range: -100 to260 c

(5)Change in radiation e.g. pyrometer range: -20 to 5760 c

THERMOCOUPLE:

Thermocouple is an instrument to measure temperature which works on thermoelectric

effects. In its construction two dissimilar conductors electrically insulated except at hot

junction where conductors may either be soldered or welded together. A refractory and

metal protective cover is provided to protect the thermocouple from injurious furnace

gases and to prevent from mechanical damages. The leads allow the measuring

instrument to be placed at considerable distance from thermocouple. The cold or the

reference junction provided by the instrument is used for measuring e.m.f. The hot

junction point is placed into a hot well i.e. the system to be measured. Due to difference of

temperatures at hot and cold junction points, an e.m.f. is generated and electric current

flows through the circuit. The value of this generated current can be read on the calibrated

meter in terms of temperature.


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THERMISTOR:

Thermistor is a contraction of term Thermal Resistor. They are essentially

Documents

Mmm_manual_4th Me-i and Me-II