Least Count (LC): 1 MSD - 1 VSD If n VSD divisions = (n-1) MSD divisions, then 1 VSD = $\frac{n-1}{n}$ MSD LC = 1 MSD - $\frac{n-1}{n}$ MSD = $\frac{1}{n}$ MSD

Typical values: If 1 MSD = 1 mm and 50 VSD = 49 MSD: LC = 1/50 mm = 0.02 mm = 0.002 cm

Standard vernier: 10 VSD = 9 MSD, LC = 0.1 mm = 0.01 cm

Reading: Measurement = MSR + (Vernier coincidence * LC)

Zero error:

• Positive: Zero of vernier is to the RIGHT of zero of main scale. Correction: subtract.
• Negative: Zero of vernier is to the LEFT. Correction: add.