Explanation: Dial gauges are only used as comparators and should not be used as direct measuring instruments. It provides only relative measurement. These are used to check consistency and accuracy in manufacturing processes.

Explanation: When the plunger lifting lever raised to allow work to be inserted under the contact point, then after completing this it must be released slowly. Sudden release will distort the rack teeth.

Explanation: Oiling and greasing are not desirable in plunger of dial indicator. Oiling of plunger will only result in picking up of dust and sticking. The plunger should never be greased or oiled.

Explanation: A dial indicator could be mounted either by the back or by the stem. Back mounting of dial indicator provides more positive clamping. It is preferred where fixture design mount permits adjustment and space is limited.

Explanation: If the dial gauge is clamped by the steel stem, then a great a clamping force will cause the jamming of plunger in the stem. The fixture hole must be smooth and true to avoid distortion, locking and binding of stem in it.

Explanation: The contact points are made of hardened steel and blackened to avoid rusting. To prevent scratching of workpiece, the contact end is polished. The general purpose contact point is of spherical shape.

Explanation: The dial indicator should be accurate to within ±1 graduation with 2.3 turns, that is the variation of the actual object size with the setting master is displayed by the pointer position with a maximum error of ± 1 graduation, at any position within 2.3 turns.

Explanation: If contact points of dial gauge are worn, then it should be replaced as early as possible. The surface of flat contacts should be square truly to the plunger and for accurate reading should be parallel to the measuring surface of the fixture.