a vernier caliper is used for measuring the distance between two sides. thais always called it "vernier". the vernier has more accuracy and precision than a ruler. first, a vernier has outside jaws and inside jaws which are used for measuring external and internal length respectively. Second, vernier has the depth probe to measure depth. third, there are two main scales in centimeters (cm) and inches. next, there are two main vernier scales in centimeters and inches. finally, the vernier has a part retainer which is used for locking or releasing the sliding scale.
there are several steps in using the vernier. first, place the object you wish to measure in the jaws of the vernier. the position of the measurements is at the zero mark on the sliding scale pointing to on the main scale. second, read the digit (the whole number) on the main scale. third, read the first decimal on the same main scale. finally, read the second decimal on the vernier scale. remember that the second decimal comes from the position where a line on the main scale best lines up with a line on the vernier scale.