Sr.
No.

Reading at the contact edge of glass plates,

MSR(cm) + VSD = TR (cm)

(s₁)

Reading at the inner edge of thin paper,

MSR(cm) + VSD = TR (cm)

(s₂)

Length of air film, l

= (s₂ - s₁)
(cm)

Mean l
(cm)

1
2
3

0.95 + 0.027 = 0.977
0.95 + 0.010 = 0.960
0.95 + 0.020 = 0.970

4.2 + 0.025 = 4.225
4.2 + 0.025 = 4.225
4.2 + 0.025 = 4.225

3.248
3.265
3.255

3.256