Question

What is the parallel limit of blade of optical bevel protractor?

(a) 0.003mm

(b) 0.02mm

(c) 0.002mm

(d) 0.03mm

The question was posed to me in an interview for internship.

I'm obligated to ask this question of Vernier and Optical Bevel Protractor in portion Angular Measurement and Circular Division of Engineering Metrology

Answer 1

Correct option is (d) 0.03mm

For explanation I would say: Blade is moved along the turret. Working edge of blade should be parallel upto 0.03 mm and straight up to 0.02 mm and over the entire length of 300 mm. Blade can be clamped in any position.