Vernier calipers are the simplest of vernier instruments and they are veryimportant in toolroom, die-making , model-making , and similar applications. They provide long measurement ranges (6 to 80in.) and fare economical . One pair of verniier calipers can substitute for many outside and inside micrometers , but they cannot replace them.
Vernier calipers are slide calipers with a vernier scale attach├ę . Because the vernier increases its discrimination to 0.02 mm(1 mil,0.001 in.) , we need a fine adjustment and a means for a zero setting . For convenience , some instruments are graduated on one side for inside measurement and on the other side for outside measurement . The jaws of most vernier calipers are reduced to thin nibs for small inside measurement.
You can make reliable measurements with the vernier caliper , but it is not easy. The reason why a fundamental of all highly is reliable measurement is that it has to do with alignment , vernier calipers demonstrate clearly how many problems bad alignment can create.