Question

What are the requirements for the measurement of flatness using light?

(a) Monochromatic light and a pair of optical flats

(b) Dichromatic light and sets of optical flats

(c) White light and a pair of optical flats

(d) Monochromatic light and sets of optical flats

The question was posed to me by my college director while I was bunking the class.

This intriguing question originated from Flatness Testing topic in portion Straightness, Flatness, Squareness, Parallelism, Circularity and Rotation of Engineering Metrology

Answer 1

The correct choice is (d) Monochromatic light and sets of optical flats

To explain: Monochromatic light and sets of optical flats are required for measurement of flatness using light. Monochromatic light is used to get none overlapping, clear interference pattern.