Question

Which of the following is the principle of Golay cell which is used as a detector in IR spectroscopy?

(a) Expansion of gas upon heating

(b) Increase in resistance due to an increase in temperature and vice versa

(c) Temperature difference gives rise to a potential difference in the material

(d) Decrease in resistance due to an increase in temperature

I had been asked this question during an online interview.

This interesting question is from Instrumentation of IR topic in section Colorimetry and Spectrometry of Analytical Instrumentation

Answer 1

The correct answer is (a) Expansion of gas upon heating

To explain: It is also known as pneumatic detector. The gases expand on heating and this in turn leads to the movement of a diaphragm just like in pneumatic sensors.