Theory : Principle of
vernier calipers – N divisions on the vernier scale is equal to (N-1) divisions on
the main scale.
N V.S.D = (N-1) M.S.D
1 V.S.D = 
M.S.D
M.S.D
Least count (L.C) of vernier calipers : Minimum length or
thickness measurable with the vernier calipers is called its least count.
Least count (L.C) = 1 M.S.D – 1 V.S.D
L.C = 1 M.S.D – M.S.D
M.S.D
L.C = 1 M.S.D [ 1-]
]
L.C = 
= 
=
Where S is the value of one Main scale division and N is
the number of equal divisions on the vernier scale.
The least count of the vernier can be measured by using the formula stated below.
Least count (L.C) = 1 M.S.D - 1 V.S.D Example;
vernier scale is constructed by taking 49 main scale divisions dividing them into 50 divisions
ie. 49mm divided into 50 parts
therfore
1 vsd=49/50 mm=0.98mm
1 MSD=1mm
Substituting in formula
L.C = 1 M.S.D - 1 V.S.D
L.C=1-0.98=0.02mm
Hope you enjoyed this.
