Question 81Steam Plants - 1st Asst/Chief

The correct answer is B) specific weight of the flue gases. A mechanical carbon dioxide recorder operates by detecting the difference in specific weight between the air and the flue gases. The higher the carbon dioxide content in the flue gases, the higher the specific weight, which the recorder can measure to determine the CO2 levels. This is the underlying principle behind the operation of a mechanical CO2 recorder. The other options are incorrect because they do not accurately describe the mechanism by which a mechanical CO2 recorder functions. The soot content, color, or temperature of the flue gases are not the parameters that the recorder uses to measure the carbon dioxide levels.