Question

Which of the following is true for coincidence between two axes?

(a) Light weight dial indicator is used

(b) Direction of measurement doesn’t varies

(c) There is no effect of gravity force

(d) Mandrel is used to represent the plane

This question was posed to me in final exam.

My doubt is from Parallelism, Equidistance and Coincidence topic in division Straightness, Flatness, Squareness, Parallelism, Circularity and Rotation of Engineering Metrology

Answer 1

Right answer is (a) Light weight dial indicator is used

To explain I would say: Light weight dial indicator is used in this test. The direction of the measurement varies during rotation in relation to the gravity direction. The sensitivity of the apparatus to the gravity force is taken into account.