Micrometer screw gauge is a device used to measure small lengths. It has an accuracy of 0.01 mm. It has two scales; the sleeve scale and thimble scale. The sleeve scale is divided into upper and lower scales with the
upper division in mm and lower divisions in 0.5 mm. Thimble scale is divided into 50 equal
divisions each division consisting of 0.01 mm.
The reading is taken in two steps;
a) The reading on the sleeve scale is read ta the point where it touches the edge of the thimble
in mm and half mm.
b) The thimble scale is read at the point where the centre line of the sleeve is parallel to the
thimble scale division.
Examples
1. Give the reading in the following diagram.
Answer
Sleeve reading – 3.5 mm
Thimble reading – 0.45 mm
Adding up we get 3.95 mm.
2. Give the reading in the following micrometer screw gauge?
Solution
Sleeve scale reading – 4.0 mm
Thimble scale reading - 0. 32 mm
Adding up the two we get 4.32 mm.
Mutiso answered the question on
October 11, 2018 at 18:26