Page 56 - CITS - Electrician - Trade Practical

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ELECTRICIAN - CITS

TASK 2 : Measure the diameter of wire / object with micrometer
1 Fix the micrometer firmly in micrometer stand. (Micro meter stand holds micrometer firmly and prevents error
caused by shaking the micrometer OR Object while measuring the scale)
2 Open the distance between anvil and spindle by turning thimble OR ratchet.
3 Place the piece of conductor OR object whose diameter to be measured between anvil & spindle.
4 Close / move the spindle towards anvil by turning the ratchet.
5 Now, read the main scale, sub scale and circular scale and record the reading.

6 Open the micro meter spindle by turning ratchet and remove the object.
7 Calculate the diameter / thickness of object with measured readings. i.e,
Diameter = main scale reading + sub scale reading+ rotating scale reading X least count + zero error

TASK 3 : Measure the gauge of wire with standard wire gauge (SWG)

1 Take a piece of PVC copper wire and remove the insulation with electrician knife.
2 Hold the standard wire gauge and copper wire conductor whose diameter to be measured.
3 Insert the single conductor of PVC copper wire into the wire gauge slot which exactly match the thickness of
conductor, and read the SWG scale of that slot.
4 In similar way, check the diameter of different conductors of copper, aluminum, GI and record the SWG value

Safety precautions
1 Handle the micrometer carefully and do not drop it.
2 Do not over turn the thimble & ratchet of micrometer.
3 Do not measure heavy objects in micrometer.
4 Do not insert the whole wire / cable in wire gauge. Insert only single conductor.

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CITS : Power - Electrician & Wireman - Exercise 20