- #1

- 107

- 1

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter Ashu2912
- Start date

- #1

- 107

- 1

- #2

- 4,239

- 1

Interesting. I've used a vernier caliper but have never put in the effort to see how it works.

The main scale is marked off in hash marks every 0.025".

The slide has hash marks from 0 to 25. These marks span from 0" to 1.125" on the main scale when the caliper is closed.

So for 25 divisions on the slid, there are 49 divisions on the main scale

Surely, what gets the thing to work is that 25 and 49 are mutually prime.

The resolution is 0.001".

The main scale is marked off in hash marks every 0.025".

The slide has hash marks from 0 to 25. These marks span from 0" to 1.125" on the main scale when the caliper is closed.

So for 25 divisions on the slid, there are 49 divisions on the main scale

Surely, what gets the thing to work is that 25 and 49 are mutually prime.

The resolution is 0.001".

Last edited:

- #3

- 4,239

- 1

- #4

Ranger Mike

Science Advisor

Gold Member

- 2,168

- 228

- #5

uart

Science Advisor

- 2,776

- 9

Mathematically the Vernier scale works as follows.

A vernier scale containing "

Now if we open the verniers by an amount "

Expanding gives

- #6

- 4,239

- 1

- #7

Ranger Mike

Science Advisor

Gold Member

- 2,168

- 228

In fact the vernier principle ( invented by Pierre Vernier in 1631) and slide caliper design is credited to Joseph R. Brown in 1851 ( (brown & Sharpe MFG. CO).

Older " open setup " measuring systems, including the above, used the Gage Makers Rule of Ten in an attempt to eliminate the human error of measurement. This pre WW2 rule of thumb is:

Rule: The instrument must be capable of dividing the tolerance into ten parts.

The Purpose: To eliminate 99% of the instrumentation error of previous steps in measurement.

When Applied: To every step in the measurement sequence until the limit of the available instrument is reached.

The results: Fewer bad parts accepted and good parts rejected.

- #8

- 2

- 0

http://marinesite.blogspot.in/search/label/oral questions

- #9

- 1,506

- 18

If the main scale is graduated in 10 divisions the slider of the vernier is equal in length to 9 division of the main scale but is also divided into 10 equal divisions.

Whichever division on the vernier lines up with a scale division on the main scale gives the next significant figure to the main scale reading corresponding to the zero on the vernier.

ie if the zero on the vernier is between 6 and 7 on the main scale and division 8 on the vernier coincides with a main scale division then the distance is 6.8

Whichever division on the vernier lines up with a scale division on the main scale gives the next significant figure to the main scale reading corresponding to the zero on the vernier.

ie if the zero on the vernier is between 6 and 7 on the main scale and division 8 on the vernier coincides with a main scale division then the distance is 6.8

Last edited:

Share: