How to Read Vernier (English)?
How to read the English version of vernier calipers correctly? Here
are some useful tips. For the vernier calipers, the bar is graduated
into twentieths of an inch (.050"). Every second division
represents a tenth of an inch and is numbered. The Vernier plate is
divided into fifty parts and numbered 0, 5,10,15, 20, 25, . . .45,
50.The fifty divisions on the Vernier plate occupy the same space as
forty-nine divisions on the bar.
The difference between the width of one of the fifty spaces on the
Vernier plate and one of the forty-nine spaces on the bar is
therefore 1/1000 of an inch (1/50 of 1/20). If the tool is set so
that the 0 line on the Vernier plate coincides with the 0 line on
the bar, the line to the right of the 0 on the Vernier plate will
differ from the line to the right of the 0 on the bar Pg. 28-29 by
1/1000; the second line by 2/1000 and so on. The difference will
continue to increase 1/1000 of an inch for each division until the
50 on the Vernier coincides with the line 49 on the steel rule.
When you read the tool, you should note how many inches, tenths (or
.100) and twentieths (or .050) the 0 mark on the slide Vernier is
from the 0 mark on the bar.
Then you should note the number of divisions on the slide Vernier
from the 0 to a line which exactly coincides with a line on the
bar.
For instance, the Vernier plate has been moved to the right one and
four tenths and one twentieth inches (1.450), as shown on the bar
and the fourteenth line on the slide Vernier exactly coincides with
a line, as indicated on the illustration above. Fourteen thousandths
of an inch are, therefore, to be added to the reading on the bar and
the total reading is one and four hundred and sixty-four thousandths
inches (1.464).