To
read a vernier scale to 1/50 mm or 0.020 mm, the vernier scale must have 49 mm divided
into 50 equal spaces for use with 1.0 mm graduations on the true (or main) scale (
click here to see our example of verniers in a pop up window) or go to the example page and print it out for your reference.
First, look at the metric example. The
vernier "0" is between 30.4 cm (304mm) and 30.5 cm (305mm). To determine
the precise location, count across the vernier from "0" to see which line
exactly coincides with a line on the true (or main) scale. It is the 33rd line.
Therefore, the correct reading to 1/50mm is 304.00mm + 33 x .02mm = 304.66 mm (or
30.466 cm).
Likewise, for the inch vernier, to read to
0.001", one must have 50 graduations on the vernier over 49 spaces of 1/20" (or
0.05") graduations on the true (or main) scale (1/50 x 1/20 = .001").
Now, look at the inch example.
"0" on the vernier is between 12.000" and 12.050" on the true
scale. Count from "0" to the first line that coincides exactly with a line
on the true (or main) scale which is the 8th. Therefore, the correct reading is
12.000" + 8 x 0.001" = 12.008".
Other combinations of main scale graduations
and vernier graduations are possible for both inch and metric reading for these or other
resolutions. For example, for 1/10 mm (0.1mm) resolution, one needs only 10
graduations on the vernier over 9 (1mm) graduations on the main scale (1/10 x 1 = 0.1mm
resolution, etc...
For angular verniers, the same principle
applies. For 1/10º (0.1º), one may have the main or true scale divided into 360 x
1° increments; and the vernier divided into 10 graduations over 9° of the main scale.
The reading is the same as for linear scales.
Likewise, angular verniers can be used to
accurately read degrees, minutes or military units.
Click here to go to
RFQ--Request for Quotation Page
on our Whittam Scales, Verniers & Dials
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