1. How to read a Vernier Caliper
PEO LEVEL 1
How to read a Vernier Caliper

2. How to read a Vernier Caliper
The Vernier caliper is used by engineers to give precise measurements when working to extremely fine tolerances.
The Vernier caliper can be used to measure in three different ways.
External measurements
Internal measurements
Depth measurements

3. Parts of a Vernier caliper
Outside jaws: used to measure external diameter or width of an object
Inside jaws: used to measure internal diameter of an object
Depth gauge: used to measure depths of an object or a hole
Main scale: scale marked every mm
Main scale: scale marked in inches and fractions
Vernier gives interpolated measurements to 0.02 mm or better
Vernier gives interpolated measurements in thousands of an inch 0.001”.
Retainer: used to block movable part to allow the easy transferring of a measurement

4. How to read a Vernier Caliper
Ensure zero’s align exactly before taking any measurements

5. How to read the Metric Vernier scale
Firstly read the main scale. If the zero on the vernier scale is just past the 16mm on the main scale then our first figure is 16.00mm

6. How to read the Metric Vernier scale
You then need to read the Vernier scale and see which line, aligns perfectly with one of the lines on the main scale.
Vernier Scale

7. How to read the Metric Vernier scale
In this example the 2 on the Vernier scale aligns perfectly which means our second figure is 0.20mm as the Vernier scale is divided into 0.02mm increments(always check this scale as some Vernier scales differ)

8. How to read the Metric Vernier scale
If we then add our figures together 16.00mm mm our final reading would be 16.20mm As you can see when reading the Metric scale the Vernier caliper is accurate to two decimal places.

9. How to read the Imperial Vernier scale
The main scale is in inches i.e ”. It is then broken down into tenths of an inch i.e ”. And can be further broken down into twenty five thousands of an inch i.e ” And is broken down even further on the Vernier scale into thousandths of an inch 0.001”

10. How to read the Imperial Vernier scale
Thousandth of an inch 0.001”
One inch 1.000”
Tenth of an inch 0.100
Twenty five thousandth of an inch 0.025”

11. How to read the Imperial Vernier scale
Firstly read the main scale. If the zero on the Vernier scale is just past the 6/10ths on the main scale then our first figure is 0.600”

12. How to read the Imperial Vernier Scale
Once you have established how many tenths you then need count up the twenty five thousands of an inch divisions.

13. How to read the Imperial Vernier scale
If the zero on the Vernier scale is past two twenty five thousands of an inch divisions, you need to add 0.025” ” to our original figure 0.600” giving you a running total of 0.600” ” ” = 0.650”

14. How to read the Imperial Vernier scale
we now need to add in the figure on Vernier scale, the 16 on the Vernier scale aligns perfectly which means our second figure is 0.016” as the Vernier scale is divided into 0.001” increments.

15. How to read the Imperial Vernier scale
If we then add all of our figures together 0.600” ” ” ” our final reading would be 0.666” As you can see when reading the Imperial scale the Vernier caliper is accurate to three decimal places

16. Parallax Error
Be aware, that when reading a Vernier caliper two people may get a slight numerical discrepancy. This is due to parallax error. Parallax error is defined as an error in reading an instrument employing a scale and pointer because the observer's eye and pointer are not in a line perpendicular to the plane of the scale. Engineering drawings always have built in tolerances to allow for such things.

17. Metric Test
Answer
24.26mm
Answer 30.06mm

18. Metric Test
Answer
30.06mm

19. Metric Test
Answer
44.38mm

20. Imperial Test
Answer
xx.xxmm
Answer
3.229”

21. Imperial Test
Answer
1.331”

22. Imperial Test
Answer 0.936”