Page 56 - CITS - Electrician - Trade Practical
P. 56

v

                                                                                   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.









































                                                           39

                                     CITS : Power - Electrician & Wireman - Exercise 20
   51   52   53   54   55   56   57   58   59   60   61