Question

What can be done to increase the temperature range of optical pyrometers?

(a) Better accuracy of telescope

(b) Using electrical circuit for control box

(c) Inclusion of absorbing screen

(d) Using red filter

This question was addressed to me during an interview for a job.

Origin of the question is Pyrometry and the Types of Pyrometers topic in chapter Tools of the Metallurgist of Engineering Material & Metallurgy

Answer 1

Correct option is (c) Inclusion of absorbing screen

The best I can explain: Optical pyrometers have a temperature range of 1400-2400 F. This range can be improved by using an absorbing screen between the lens and the filament. Therefore, by using various absorbing screens the range can be increased to be over 10000 F.