Measuring instruments and their use. Calipers, scale, tri-square, Inside and outside micrometers, feeler gauge

 

  Task:  Hand Tools and
Measuring Instruments

  Sub
Task: Identify measuring instruments and their use. Calipers, scale,
tri-square,

           Inside and
outside micrometers, feeler gauge

 

Aims:

1.    
Learn to identify
different types of measuring instruments.

2.    
What is the use of
vernier caliper and how to use it?

3.    
What is the use of
micrometer? Learn how to use micrometer.

4.    
What is the use of
inside and outside caliper?

5.    
What is the use of
filler gauge? How to use?

6.    
How to use thread
gauge.

Requirement for performing the task:

Different
types of measuring instruments required.

1.    
Vernier caliper

2.    
Thread gauge

3.    
Inside and outside
caliper

4.    
Filler gauge

5.    
Micrometer

Precaution to be observed:

1.     Make
sure the instrument is clean and make sure it works ( no forced friction between vernier scale and main scale)

2.     Check
for Zero error( error resulting in the
wrong collaboration of the instrument)

3.     The
screw should never be tightening too much.

4.     Some
modern micrometers are fitted with a ratchet to avoid this, but in orlder
models it is possible to damage the screw by over tightening.

5.     All
the instrument should be free from oil and dust.

6.     All
measuring instruments should be kept in their respective box.

1. Vernier Caliper: It is used to measure the inside, outside diameter, depth and thickness.
2. Inside Caliper and Outside Caliper: It is used to measure the inside and outside diameter.	3. Feeler gauge: It is used to measure the clearance between two surfaces. Used for tappet clearance in engine.
4. Micrometer: There are two types of micrometer used onboard ship. Inside micrometer is used to check the internal diameter and outside micro meter is used to check the outside diameter.