Question

Which of the following is true for flat surface of flat contacts in dial gauges?

(a) Should be parallel to the plunger

(b) Should be truly square to the measuring surface of fixture

(c) Should be square to the plunger

(d) Should be perpendicular to the measuring surface of plunger

I have been asked this question in quiz.

The doubt is from General Care of Dial Gauges in chapter Dial Indicators and Indicating Gauges of Engineering Metrology

Answer 1

The correct option is (c) Should be square to the plunger

The explanation is: 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.