Question

Which of the following is true about the material used for making parts in test indicators?

(a) No part is made of plastic

(b) All parts are made of hardened steel

(c) Cover over the dial face is made of hardened metal

(d) Cover over the dial face is made of plastic

The question was asked in an international level competition.

The doubt is from Test Indicators in division Dial Indicators and Indicating Gauges of Engineering Metrology

Answer 1

Right choice is (d) Cover over the dial face is made of plastic

The explanation is: Plastic parts are not used on this instrument but there is an exception of the cover over the dial face which is made up of plastic. Easy to read by sharply defined dial face is present with contrasting numerals.