Question

The computation of Graham’s ratio requires the concentration values of

• A. O$_2$, N$_2$, CO
• B. O$_2$, CO
• C. CO$_2$, N$_2$, CO
• D. CO$_2$, N$_2$, CO, O$_2$

Hint:

Graham’s ratio is a critical indicator in mines to detect early signs of combustion, especially in coal mines.

Answer 1

The Correct Option is B

Graham’s ratio is a measure used in mine safety to detect the presence of underground fires or spontaneous combustion by analyzing the air composition. It is defined as the ratio of CO produced to the O$_2$ consumed, typically expressed as (CO / (0.265N$_2$ - O$_2$)) $\times$ 100, but for its basic computation, only the concentrations of CO (carbon monoxide) and O$_2$ (oxygen) are directly required. While N$_2$ (nitrogen) may be used in more complex versions of the formula, it’s not essential for the basic ratio. CO$_2$ and other gases are not part of the core computation. Thus, the correct answer is O$_2$, CO.