How do you take reading in traveling microscope?

let us think with all our common sense.

The indicator which reads the reading on the main scale is the zero mark on the vernier.

On the main scale each mm is divided into half mm. Hence the reading would be read for divisions on the main scale. ie say I start from 3 cm.

3 cm, 3.05 cm, 3.1 cm, 3.15 cm, 3.2 cm, 3.25 cm and so on.

But for our convenience let us read as 3.000 cm, 3.050 cm, 3.100 cm, 3.150 cm, 3.200 cm, 3.250 cm and so on,

Now say your indicator ie zero marking on the vernier is lying in between say 3.200 and 3.250 cm. Then main scale reading would be recorded by taking the lower value namely 3.200 cm.

Now the vernier would give the last two decimal values for accuracy. If the 43rd division on the vernier get coincided with some line on the main scale, then the vernier reading will be got by multiplying this vernier coincidence 43 by the least count. The least count will usually be 0.001 cm.

So the vernier scale reading will be 0.043 cm

Now by adding this along with the main scale reading ie 3.200 cm we get 3.243 cm.

Another example: If suppose the indicator lies in between 6.450 and 6.500. The vernier division 17 get coincided.

Main scale reading is 6.450 cm

Vernier scale reading is 0.17 cm

So the total reading ie accurate reading is 6.467 cm

UNNATI CHANDANE

STD:XII