How to read a metric vernier caliper
The Vernier Caliper is a precision instrument that can be used to accurately measure internal and external distances. The example shown below is an analog vernier manual where measurements are interpreted from a scale. This type of vernier is more difficult for the user to use than a digital vernier caliper with a readable digital display displayed. Models used are available in both imperial (inch) and metric (mm) sizes. Analogs are still available for purchase and are still popular because they are much cheaper than digital versions. Additionally, digital systems require batteries while analog ones do not require any power source.
STEP 1 Check Vernier before use.
Check the default value of the vernier caliper by moving the vernier caliper jaws completely. Then check for damage of the mouth of the temple. Vernier by Check the survival of light. If light escapes, Vernier’s mouth is damaged. and should not be used to measure the workpiece.
STEP 2 Look at the main scale.
the scale is 1:100, that means the graved numbers are the hundredth part of meter or the centimeter – bigger marks, that it was subdivided by ten -smaler marks, the millimeter. The vernier has twenty spaces between vertical marks, so, it divides by twenty the millimeter, the smaler division of the main scale, obtaining five hundredths of millimeter 0.05 mm.
the smaller division of the main scale – fixed scale – is the millimeter, that was divided by twenty divisions of vernier.
Resolution = 1 mm / 20 = 0.05 mm
The resolution of this is five hundredths of millimeter 0.05 mm.
STEP 3 How to read a metric vernier caliper
Graduation 0.05 mm.
(1) Main Scale 13 mm.
(2) Vernier Scale 0.50 mm.
Reading 13.50 mm.
Read the measurement result at the Main scale.
Notice where the bottom zero “0” of the Vernier scale corresponds to the range of the main scale at the top. From the figure, it can be seen that The lower center scale corresponds to the upper key scale in the range 13 mm to 14 mm, so we can read the value on the main scale 13.00 mm.
Read the measurement result on the Vernier scale.
Notice at the bottom scaling position of all vernier scales which scale corresponds to the upper key scale the most. From the figure, it can be seen that the lower scale line of the 10th vernier scale corresponds to the main scale line above the most.
Therefore, we will read the value at Vernier scale can be obtained by taking the resolution of the tool. Multiplying the bottom scaling line of the vernier scale read is 10 scale x 0.05 mm resolution equals 0.50 mm.
Take the measurement result read from the main scale + the measurement result read from the vernier scale is 13.00 mm + 0.50 mm equals 13.50 mm.