ANJALAI AMMAL MAHALINGAM ENGINEERING COLLEGE

KOVILVENNI THIRUVARUR (DT) PIN: 614 403

ISO 9001:2008 CERTIFIED

LAB MANUALDegree: B.EYear / Sem: III / IVCourse: Mechanical EngineeringSubject Code: ME6513Subject: METROLOGY AND MEASUREMENTSLABORATORYME6513 - METROLOGY AND MEASUREMENTS LABORATORYLT P C

0 0 3 2

Objective:

To familiar with different measurement equipments and use of this industry for quality inspection.LIST OF EXPERIMENTS / EXERCISES

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

2. Checking the limits of dimensional tolerances using comparators (Mechanical / Pneumatic / Electrical).

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

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

5. Floating gauge micrometer.

6. Measurement of Force and torque

7. Torque measurement.

8. Temperature measurement using thermo couples.

9. Measurement of straightness using Autocollimator.

INSTRUMENT LISTSL.NONAME OF EQUIPMENT/INSTRUMENT

1OUTSIDE MICROMETER

2VERNIER CALLIPER

3VERNIER HEIGHT GAUGE

4VERNIER DEPTH GAUGE

5SLIP GAUGE SET

6GEAR TOOTH VERNIER CALIPER

7SINE BAR

8FLOATING CARRIAGE MICROMETER

9TOOLMAKERS MICROSCOPE / PROFILE PROJECTOR

10MECHANICAL / ELECTRICAL / PNEUMATIC COMPARATOR

11AUTOCOLLIMAETOR

12TEMPERATURE MEASURING SETUP

13FORCE MEASURING SETUP

14TORQUE MEASURING SETUP

15BORE GAUGE

EXERCISE LISTS.NONAME OF EXPERIMENT

Page No

1Determination of Pitch and Tooth Depth of a Screw Thread using tool makers microscope.

2Measurement of the various dimensions by using Electrical comparator

3Calibration of dial gauge and measurement of component [ mechanical comparator]

4Pneumatic comparator

5Measurement of taper angle by using sine bar

6Calibration of gear tooth vernier and measurement of gear tooth thickness by gear tooth vernier caliper

7Floating gauge micrometer

8Calibration of depth gauge, vernier height gauge and measurement of the component

9Measure the force/load using force measurement trainer

10Measure the torque using torque measurement trainer

11Temperature measurement

12Flatness and straightness checking using autocollimator

TOOL MAKERS MICROSCOPEDetermination of Pitch and Tooth Depth of a Screw Thread

Date:

Exp No: 1Aim:

To determine the pitch and tooth depth of the given screw thread using tool maker's microscope.

Apparatus Required

1. Tool Maker's microscope

2. Screw thread

Description:

The tool maker microscope is based on the principle of optics. The microscope consists heavy

hollow base which accommodates the illuminating unit underneath and above on the top surface of the base. The worktable carriage is supported on balls and controlled the micrometer screw. The base is a column which carries a microscope unit and various interchangeable eye pieces. Light from the lamp to the centre as this instrument and is reflected as parallel beam by the prism at the end of the tube on its way up this beam collects the image of the object to the inspected and this enters the microscope being turned by another prism up to the inclined eye piece, Here the inspection may be made by eye in the normal way for the projection attachment may be fitted which turn the beam by mirror to bring up the image on the back of the translucent screen. The magnification obtained depends up on the objective of the microscope but instruments are commonly supplied which facilitates to give magnification from l0X to 100X on the projection screen.

Procedure

1. First fix the screw thread in the toolmaker's microscope. The range of the micro meter is 0 to

25mm and keeps it around 12.5mm so that we can measure in either direction.

2. Adjust the screw on the table such that the crest of the screw coincides with the horizontal

cross line and take the initial reading. Move the micrometer till the horizontal cross line

coincide with the crest of the other side. Take the final reading. The difference between the

initial and final readings gives the outer diameter and this is repeated at five different places.

3. Adjust the screw thread on the table such that the vertical line coincided the crest of one

thread and note the reading.

4. Move the micrometer till the cross line vertically coincides with the crest of the next thread

and the reading is to be noted. The difference between the initial and final readings gives the

pitch and this is repeated at five different places.

Tabulation: pitchSl noInitial reading in micrometerFinal reading in micrometerNominal value(final-initial value

1

2

3

4

Tooth depth

Sl noInitial reading in micrometerFinal reading in micrometerNominal value(final-initial value

1

2

3

4

RESULT:

Thus the given screw thread is checked for pitch and tooth depth.ELECTRICAL COMPARATOR

Date:

Exp No: 2AIM:

A vast range of measuring high precision instruments are now available. Any variation from that of the present standard dimension can also be measured with instruments called as Comparators. Electrical comparator is used for the purpose of comparison of dimensions with the standard dimension.

OPERATION: It operates on the principal of the change of inductance of a coil by the movement of a steel armature, which is moved by a plunger in contact with the surface to be checked. Two of the bridges are between armature and two are outside. These four inductances form a bridge. Initially the inductors are set so that no resultant current flows through them. When armature is moved, the balance of bridge is disturbed and a resulting current flows which is calibrated in terms of length of movement of the plunger

APPARATUS REQUIRED: Electric gauge head employing two arms of bridge armature and feeler.

1. Ammeter, voltmeter

2. Power supply.

3. Specimen holder.

CONSTRUCTION :

The variac is controlled by induction bridge, which is used to change the magnification. Electromagnets are near the armature that it will be sensitive one and will have higher magnification and when it will be at distance from steel armature then magnification will be less. Thus adjusting the variac magnification is changed.

PROCEDURE :

1. Switch on the Main Supply

2. Adjust the Specimen holder to required position.

3. Set the zero setting by adjusting the Variac4. Now keep the Sample Test Work piece on the Specimen holder. Note down the Ammeter reading

5. The difference in the ammeter reading is the difference of your standard work piece and Sample test work piece

6. Repeat the experiment for different Specimen Samples using the above procedure

PNEUMATIC COMPARATOR

Date:

Exp No:3AIM:

Theoretical Aspects

Comparator means compare the product to its standard and find the deviation form the

Standard value. There are different types of comparator to measure various dimension in

different method ( pneumatic, electrical, Mechanical, Optical)

Description of equipment

The equipment consists of two setting master for setting lower and higher value limits.

One is set to be lower limit let us 01 and another is higher limit let us 009. Depend upon the

Pressure variation this to be held and changed in to scale as in microns.

Experimentation

Experimentation

1. The equipment consists of two setting master for setting lower and higher value limits.

2. One is set to be lower limit let us 01 and

3. Another is higher limit let us 10.

4. Depend upon the pressure variation this to be held and changed in to scale as in microns.

5. The variation is brought you by change value in CAL button in the display.

6. Now using above. Do some hole drilling on your own piece and check whether they

Accepted or not

Result:

Thus the Pneumatic comparator is studied and find the resolution for various settings.

Mechanical Comparator (Dial Gauge)

Date: 4Exp No:

Aim:

Comparing the height of given samples by using mechanical comparator.

Description:

A dial gauge typically consists of a graduated dial and needle to record the minor increments, with a smaller embedded clock face and needle to record the number of needle rotations on the main dial. Typically the resolution is 0.01 mm and maximum range depends on the length of the probe which is usually of the order of 1 10 mm. The probe (or plunger) moves perpendicular to the object being tested by either retracting or extending from the indicators body. As the probe moves, it rotates a gear mechanism within the gauge which rotates the needle. The dial face can be rotated to any position, this is used to orientate the face towards the user as well as set the zero point.Experimental setup:

1. Place the standard piece on the stand and set zero indication on outer ring and 1 on inner circle for that piece.

2. Now insert the test pieces and check whether it shows zero or any deflection from zero. Accept these piece when the changes are in between 90 to 10 ( -10 to +10)

3. Otherwise reject pieces

4. Now compare the other products with reference to standard piece

5. Give final report,

Tabulation for mechanical comparator

Sl noReading from dial gaugeAcceptable rangeRemarks(acceptable or not)

1

2

3

4

Tabulation for dial gauge calibration.

Sl noReading from dial gaugeSlip gauge value in mmError%of error

1

2

3

4

Result:

Thus the height of given samples are compared by using mechanical comparator.

DETERMINATION OF TAPER ANGLE BY USING SINE BAR

Date:

Exp No:5AIM:

To measure the taper angle of the given specimen using sine bar method.

APPARATUS REQUIRED:

1.Sine bar4. micrometer

2.Slip gauge set5. surface plate

3.Dial gauge with6.Vernier caliper

stand

FORMULA:

Sin = h / L

Where,

H - Height of the slip gauge

L - Distance between the centers - Inclined angle of theSpecimen PROCEDURE:

The given component is placed on the surface plate.

One roller of sine bar is placed on surface plate and bottom surface of sine bar is seated on the taper surface of the component.

The combination of slip gauges is inserted between the second roller of sine bar and the surface plate.

The angle of the component is then calculated by the formula given above.

TABULATION:Sl.NoLength of the sine bar (L) mmHeight (h)mmTaper angle ( )

1

2

3

4

5

CALCULATION:

Sin = h / L

RESULT:

Thus the taper angle of the given specimen is measured using sine bar.

The external taper angle is ________________________

MEASUREMENT OF GEAR PARAMETERS USING

GEAR TOOTH VERNIER

Date:

Exp No:6AIM:

To measure the gear parameters using Gear tooth vernier.

APPARATUS REQUIRED:

Gear tooth Vernier, Gear specimen.

SPECIFICATION:

Gear tooth Vernier: Range = Horizontal =0-40 mm

Vertical = 0-20 mm

L.C= 0.02 mm

FORMULA:

1.W

=NM sin (90/N)

2.d

=NM

---------

2

3.M

=D

-------------

(N+2)

Where W = Chordal width of tooth in mm

d = Chordal addendum of gear in mm

M = Module of gear in mm

N = NO. Of teeth

D = outside Dia in gear in mm

PROCEDURE:

The N, D of the given gear block are measured.

The module M is then calculated.

Theoretical values of W and d are computed.

Theoretical values of W is set in horizontal Vernier scale of gear tooth Vernier and corresponding actual d value is measured in the vertical scale.

Theoretical values of d is set and actual W is measured along Horizontal scale.

This procedure is repeated for 5 teeth and value tabulated.

Gear tooth vernier

Outside Diameter of Gear

TRIALOUT SIDE DIAMETER D mm

1

2

3

4

5.

Measurement of Addendum and Chordal Width

TrialChordal addendum d mm Chordal width w mm

ActualTheoreticalActualTheoretical

1

2

3

4

5

RESULT:

Thus the Chordal thickness and addendum of the gear are measured using gear tooth vernier.

Theoretical Values:

Chordal addendum of gear = mm

Width of gear tooth = mm

Actual Values:

Chordal addendum of gear = mm

Width of gear tooth = mm

FLOATING CARRIAGE MICROMETER

Date:

Exp No: 7PART DESCRIPTION

BASE: This is a hardened and stabilized steel plate having three adjustable supporting Knobs/Leveling screws (E) at the bottom. This base has two integral V grooves on top.

One is used to guide a steel ball and another for pegs or pins (2).

On this base, two vertical columns are provided which have large V groove (main 'V Groove) in the center located on top. Two levers (4) are provided on top of the cover plate of the both side columns (D) .This accommodates centers (3) to hold work piece

INTERMEDIATE PIECE/CARRIAGE: - This has two pegs/pins (2) at one-side & Stoppers with flat guide on other side provided at the bottom. On top this has two parallel vee grooves.

FLOATING TOP:- This has one 'V groove on one side and short length flat guide on other Side at the bottom. On top, it has two large V grooves. Out of these two V grooves, one is used to accommodate Zero indicator (F) and other is used to accommodate Micrometer (G). Here again two levers (4) are provided for easy adjustment of Zero Indicator (F) and Micrometer (G).

ASSEMBLY PROCEDURE:-

Clean all parts with tissue paper or soft cloth. Put the base (A) on a firm leveled table or surface plate. Level the machine with help of leveling screw (E) in such a way that the floating top remains steady at any position without gravitational movement locate the carriage (B) or intermediate piece on two V grooves of base such that V pins/pegs (2) of carriage (B) are on one side of 'V groove and put a steel ball (1) on 'V groove between two stopper pins on base & underneath of carriage so that the carriage is well balanced and free to slide on base. Put Floating top (C) on the carriage with two balls between two stopper pins on one side of groove of carriage (B) and floating top (C). then put one ball on other V groove of carriage ( B) and below the flat surface on other side of floating top between stepped pins. Insert two centers (3) from both sides on the V groove provided on top of column ( D)

Insert the Micrometer (F) provided with machine in one side of floating top nearer to observer and tight lever (4) & Alien screw provided on floating top (C). Insert the Zero Indicator (G) on the other side of V groove on floating top and tight lever & Allen screw. Insert pillar ( 5) in holes provided on upper surface of cover of floating top. Tight hock holder (6) on pillar insert hook in hook holder and tight knob of hook holder. Hold the setting master ( 8) in between the centers and tight levers provided above the column. Now machine is ready to take actual readings.

Know your micrometer

Micrometer provided with this machine has (two types of readings. One reading Like from the main scale and drum, and second from vernier scale main scale is on fixed barrel of the Micrometer (non-rotary part of the micrometer) Main scale is having graduations of one-millimeter sub ivided by half-millimeter lines. It is also provided with a vernier scale. Each Vernier line reads 0 001 mm

MAIN SCALE with VERNIER

Drum has 50 divisions and each division reads 0.01mm. Every 10'" line-has marking

from 0-10. so least count for vernier is 0.001 mm.

MICROMETER READING EXAMPLE

Crossing line on Main scale is 11 & half

Main Scale Read 1 1. 00

+00 500

= 11.500

Crossing line on Drum with horizontal, Zero line is Ist line

Drum reading = 5 x 0.01

= 0.05

Matching line on Vernier scale is 4th line

Vernier reading 0 .001 x 4

= 0 .004

Hence Reading is 11.500 + 0.05+0.004

= 11.554mmMEASUREMENTS AND CALCULATIONS,

Major Diameter measurement:-

The diameter of the setting master or a cylinder should be nearly same as the diameter of the Thread gauge. The advantage of using setting master is it gives similarity of contact at anvils and reduces errors in measurements..(Due to short travel of micrometer, particularly pitch error in micrometer is minimized.) The setting master is held between enters. Take the reading of the diameter Say, this reading is "M" The master cylinder is then replaced by a threaded work place or thread gauge and again second readings taken Say this reading is "W"

If

D = Diameter of setting master

M =Micrometer reading over setting master.

W = Micrometer reading of threaded work space.

Then

Major diameter = D (M W)

Example: - 1

We have to check a thread gauge say, M16 x 2. We have 3 setting master or cylinder of size 16.20mm. Say micrometer reading obtained on this master is 5 24mm (M) When replaced with thread plug gauge of above and the reading is taken in the same Manner and our reading is 5

04mm then in our case,

D = 16.200

M = 5.240

W = 5.040

Major Diameter of the gauge: under inspection say, "OD"

OD = 16.200 - (5.20-5.04).

= 16 200 - 0.16

MEASUREMENT OF MINOR DIAMETER (Core Diameter)

Minor diameter is also measured by comparative pieces as above but using prism with Micrometer in addition. The prisms used for core diameter measurements are of hardened steel and have angle of 45, with the front edge finished to a radius some what smaller that that of curvature at the root of the threads to be measured. Details of the size recommended are given in the chart at the end (Appendix 1)

Place the suitable cylindrical standard between centers. Hang the required set of prism on the hooks provided on both sides of standard. Take the reading on micrometer and zero indicator in such a way that radius portion of prism touches master and flat portion of prism is on micrometer & zero indicator.

If

Mp = Reading over master and prism

Wp = Reading over work piece and prism

D = Diameter of master

C (MD) = Core or minor diameter of the work piece

Then,

C = D 2 [(Mp Wp) + (M W)] Measurement of Effective Diameter by using two-wire method

The process adopted in measuring effective diameter is similar to that just described Minor diameter, except that two small wires or cylinders are used in place of prisms. 1 Cylinders or wires should be chosen so that, when placed between the threads, they should contact about halfway down the flanks. Suitable sizes of these cylinders for various threads are given at the end. (Appendix- 1) The readings are taken in the same fashion as described earlier The effective diameter E is then obtained from me measured value of "T" & P by formula

E = T + P

Where T = D - (Mw-Ww)

Where,

E = Effective or pitch diameter

T = Measured dimension under cylinders

Mw = Reading measured over setting master with wire

Ww = Reading measured over work piece over wire

'w' = Mean diameter of the cylinders or wires used.

'P' = Constant depending on the pitch and angle of the thread, and the mean diameter of wires used. (Ready "p" values for different threads are given along with wires to be used.)(Appendix-1) = 0.39 mm

p' = pitch of thread

Formula for calculating "P" is P = p cot- (cosec-1) w

For ISO Metric or = 60 "V" threads this becomes P ' = (0.5773 x p) - w For With worth threads. Where = 27 P = (0..56369 x p) - (1.16568 x w)

Note: This formula is applicable only for parallel screw thread.

Example:-

Say. we have to check a thread plug gauge M16x2 pitch . then by referring appendix 1.

1. We have to use measuring wire size of 1.35 mm and P value as 0.1954

2 We have to use a set of prism "D" required for 2 mm pitch

3 We have a setting master of the size 16 000 mm

Now we shall take all required readings discussed earlier, for Major Diameter root

Diameter and Effective Diameter.

1. Readings for Effective Diameter. (Pitch Dial.)

D = 16.00: Mw = 18.700 Ww = 17.056

T = D (Mw Ww)

= 16.00 (18.700 - 17.056) = 14.356

E = T + P P = 0.362 taken from "Appendix- E = 14.356 + 0.1954 = 14.718MEASUREMENT WITH VERNIER HEIGHT GAUGE

Date:

Exp No: 8AIM:

1. To measure the height of the object using vernier height gauge.

2. To measure the depth of the object using Depth gauge.

INSTRUMENTS USED:

1. Surface 2. Vernier height gauge 3. Specimens 4.Depth Gauge

THEORY:

Vernier Height Gauge:

Vernier height gauge is a sort of Vernier calipers equipped with a special with a base and other attachment, which make the instrument suitable for height measurement. Along with sliding jaw assembly arrangement is provided to carry a removable clamp.

The upper and lower surfaces of the measuring jaws are parallel to base, so that it can be used for measurements over or under surfaces.

The vernier height gauge is mainly used in the inspection of parts and layout work. The vernier height gauge can be used to scribe lines at certain distance above surface with a scribing attachment in pace of measuring jaw. Dial indicators can also be attached in the clamp and many exact measurements can be made as it exactly gives the indication when the dial tip is touching the surface. Surface plates as datum surface are used for the above measurements.

PROCEDURE: 1. Place the object and the vernier height gauge on the surface plate.

2. Note the value on the scale when the moving jaw is touching the bottom of the object.

3. Take the moving /sliding jaw to the top of the object and note down the value on the scale.

4. The difference between 3&2 will give the height of the object.

PRECAUTIONS:

1. The height gauges should be kept in their case when not in use.

2. Measuring jaws should be handled carefully.

Sl noMain scale reading MSR(mm)Vernier scale reading VSR(mm)Measured reading-MSR+(VSR xLC)

1

2

3

4

5

RESULT:

The heights of the given objects measured with vernier height gauge are tabulated above.

MEASUREMENT OF FORCE / LOAD USING FORCE MEASUREMENT

TRAINEREx. No: 9Date:

Aim:To measure the force/load using force measurement trainer.

Apparatus Required:1. Force Trainer Kit, 2. Control Unit, 3. Weight Pan, 4. Loads

Procedure:1. Plug the power chord to AC mains 230V 50Hz. And switch on the instrument.

2. Place the CAL position in maximum range and make zero in direct plan meter (DPM) using

Zero knob.

3. Connect the weight pan resistance in the force cell arrangement in the control unit.

4. Place the loads one by one on the weight pan and note the DPM reading.

Graph:Plot the Actual reading Vs Indicated reading.Tabulation:Sl.noActual Reading(kg)Indicated Reading (kg)Error = Actual Indicated ReadingError %

1

2

3

4

5

Calculation:Error % =Error/Actual Reading * 100

Result:Thus the force/load using force measurement trainer was measured.

MEASUREMENT OF TORQUE USING TORQUE MEASUREMENT

TRAINER

Ex. No: 10Date:

Aim

To Measure the torque using torque measurement trainer.

Apparatus Required

1. Torque Trainer setup, 2. Control Unit, 3. Fulcrum Arm 4. Weight Pan, 5. Loads

Procedure

1. Check connection made and switch ON the instrument by rocker switch at the front panel.

The Display glows to indicate the instrument is ON.

2. Allow the instrument in ON position for 10 minutes for initial warm-up.

3. Adjust the potentiometer in the front panel till the display reads 00.0

4. Apply load to the Fulcrum arm by adding dead weights in steps of 100g.

5. The instrument read the load on the sensor and displays through LED. Readings can be tabulated.

Graph:Plot the Actual reading Vs Indicated reading

Tabulation:Sl.noActual Reading(kg)Indicated Reading (kg)Error = Actual Indicated ReadingError %

1

2

3

4

5

Calculation:Error % =Error/Actual Reading * 100

Result:Thus the torque using torque measurement trainer was measured.

THERMOCOUPLE

The THERMO COUPLE is one the simplest and most commonly used methods of measuring process temperature .the operation of a thermocouple is based upon see back effect .see back discovered that when heat is applied to junction (hot junction) of two dissimilar metals, an emf is generated which can be measured at the other .junction (cold junction).the two dissimilar metals form an electric circuit, and a current flows as a result of the generated emf.CONTRUCTION OF THERMOCOUPLE:-

A pair of two dissimilar metals that are in physical contact with each other form a thermocouple .these metals may be twisted, screwed penned, clamped or welded together .the most commonly used method for fabricating is to weld the metals together Thermocouples do not use bare conductors except in applications where atmospheric conditions permits their use .these condition obtained when temp. to be measured are low and the atmosphere is non - corrosive . Industrial thermocouples employ protective sheathing surrounding the junction and a portion of the extension leads. The leads and the junction are internally insulated from the sheath, using various. Potting compounds, ceramic beads or orides .the type of insulation used depends upon the process being monitored.

TYPE OF THE SENSORS:- "J" TYPE ,"K" TYPE, "T"TYPE

Material Used: - Chromium AlumelControls & operations

MIN: 10k single turn potentiometer to set the min.

Level of temperature (i.e. ambient temperature)

MAX: 10 k single turn potentiometer to adjust the maximum level of the temperature .

THERMOCOUPLES: Screw type connecting socket to connect the J/ K /T SENSORS

OPERATION:-

1. Select the J I KIT Thermocouples by selector switch.

2. Connect the J I KIT Thermocouples to the sensor socket provided at the front panel

3. Set the min pot to read the ambient temp. in display.

4. Insert the J I KIT Thermocouples in the HOT bath.

5. 3 1/2 Digit LED display shows the temperature obtaining at the HOT Bath directly in c.

6. If necessary adjust the MAX pot for the maximum level of temperature calibration.

7. Recorder Red & Green terminals for the analog output.

8. Fuse holder provided to protect the circuit from the over load (500 Ma)

NOTE:-

DO NOT OPEN THE FUSE CAP WHILE POWER CHORD IS CONNECTED TO 230 V AC MAINS.

MAIN CHORD:-

3 Core 3 pin cable provided to connect the mains.

TEMPERATURE MEASUREMENT STEUP

Ex. No: 11Date:

AIM: - Study temperature transducer Thermocouples J/ K/T by using digital temperature Indicator.

APPARA TUS REQUIRED: Temperature transducers, digital Temperature indicator,

Thermometer, Electric Sterlizer

PROCEDURE: - Refer Operation.

TABULAR COLUMN:-

SL NOJ type Reading in c.K type Reading in c.T type Reading in c.Thermometer Reading in c.

1

2

3

4

5

GRAPH: - l. Thermometer Reading vs J type reading.

2. Thermometer Reading vs K type reading.

3. Thermometer Reading vs T type reading.

MEASUREMENT OF STRAIGHTNESS USING AUTO COLLIMATOR

Date:

Exp No: 12AIM:

To measure the flatness with the use of Auto-Collimator

APPARATUS REQUIRED: Auto collimator

Straight edge with 100mm marked intervals.

SPECIFICATIONS:

Objective focal length

: 300 mm.

Objective clear aperture

: 25 mm

Barrel dia

: 38 mm

Barrel length

: 200 mm

Eyepiece magnification

: 10x

Measuring range

: 25 minutes

Read out

: on direct graticule AT 1

Telescope length

: 380 mm

Illuminating bulb rating

: 6 volts, 10 watts comes with transformer

Dimensions of base

: solid rugged C.I base (75x 250mm)

PROCEDURE:

1. Clean the surface plate or table.

2. Position the auto-collimator in line with the reflector. Switch on the lamp in the

3. The alignment between the auto-collimator and reflector should be checked at both extremes of the operational distance to make certain that the target graticule is contained within the eyepiece field. Fix a guide strip to control the horizontal displacement of the reflector and minimize the movement of the target graticule.

4. Mark off the positions along the surface plate equal to the pitch positions on the reflector base (in this case 100 mm). Column 1 should indicate this position.

5. At the initial position takes the reading and tabulates (column 2)

6. Move the carriage (reflector) to the next position and again tabulate the reading.

7. This method is to continue until the final outward position is recorded.

8. The remainder of the table should be filled by adopting the following procedure:

Column 3: This is the variations of the tilt occurring between the position at which the reading is taken and the original position.

Column 4: The angular position in column 3 is converted into a linear measure (1 second = 0.5 micro m). Insert a zero at the top of the column to represent the datum.

Column 5: This is the cumulative algebraic sum of the displacements. Calculate the mean displacement this is the amount by which the displacement must be adjusted to relate them to the zero datum.

Plot the values of column 5 versus column 1.

OBSERVATION:

12345

Position Of ReflectorAutocollimator ReadingDifference From 1st ReadingRise Or Fall Per 100mmCumulative Rise Or Fall

mmSecondsSecondsmm

000

0-100

100-200

200-300

300-400

400-500

500-600

600-700

700-800

800-900

900-1000

RESULT:

Thus the flatness of the surface is determined using autocollimator. EMBED Word.Picture.8

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