TRAVELLING MICROSCOPE
Instructed by: Mr. Janindu Fernando
Date of Per. : 10/03/2025
Date of Sub. :10/03/2025
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Name: Lonath piyasi wadanambi
Index No.:35751
Batch:25.1
Department: computer system engineering
A travelling microscope is an instrument for measuring length with a optical resolution it use
to measuring scales very clearly and correctly. The microscope can be moved both of
horizontal and vertical directions so travelling microscope can measure both of directions
measurements
PRACTICAL
1) Finding the internal diameter of a capillary tube
2) Finding the internal diameter of rubber tube
3) Finding the external diameter of rubber tube
MATERIALS AND APPRATUS
1) A travelling microscope
2) A capillary tube
3) Wire
4) Spirit level (some travelling microscopes have water level on its base)
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PRACTICAL METHODS
First, we determine the least count of our travelling microscope with below formula and our
instrument level with table using water level and adjusting levelling legs.
LEAST COUNT = (1 - n/N) x length of a smallest division of main scale
After we set a capillary tube to stand and align microscope with eye level and focus
microscope to capillary tube face. in that step we face a problem to focusing microscope. We
are searching for the answer for that problem and after we are flashing a torch other face of
capillary tube and focus with microscope after turning off that and better focus with fine
adjustment crew.
After we align reflection of capillary tube with cross lines and we get measurements with
moving horizontally and vertically travelling microscope.
Reading vertical scales by the vertical main scale and vertical vernier scale read horizontal
scales by the horizontal main scale and vernier scale
Remember don’t move travelling microscope all the time of getting measurements, and
measurements are relative to the observer vision so get values from same observer.
At the moment of reading values on main scale and vernier scale on travelling microscope is
harder than reading vernier caliper and micrometer screw gauge so very careful with reading
values. We use hand lens for reading measurements.
Like vernier caliper and other instruments, the vernier scale does not have to be set to 0 at the
beginning of the measurement because we are measuring by the difference of two values
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READINGS OF PRACTICAL
Least count = 0.01
Finding the internal diameter of a capillary tube
Finding the internal diameter of rubber tube
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Finding the external diameter of rubber tube
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