3.10 Textbook of Enginnering Drawing------------------
O.54+2.S=3.34lcm
O.SSkm
o 5 10
LENGTH OF THE SCALE 150 mm
SCAlE:1:40000
Fig. 3.10 Forward Reading Vernier Scale
Problem 9 : construct a vernier scale to read metres, decimetres and centimetres and long
enough to measure upto 4m. The RF of the scale in 1120. Mark on it a distance of 2.28 m.
Solution: (Fig 3.11)
Backward or Retrograde Vernier scale
- The smallest measurement in the scale is cm.
Therefore LC = O.Olm - Length of the scale = RF x Max. Distance to be measured
1 1
= - x 4m = - x 400 = 20 em
20 20
3
LeastCO\.llt= O.01m
Rf" 1120
Fig. 3.11 Backward or Retrograde Vernier Scale