Where must the record of the values or trends of gas concentrations detected by the gas monitoring system be kept?

• A. At the surface of the mine where the record can be easily accessed by coal mine workers and in a way the record can be easily read by the workers
• B. In the underground control room only
• C. In each underground crib room
• D. In the mine library

Answer: (A)

The main idea here is that records of gas concentrations need to be accessible to the people who work in the mine so they can read and respond to dangerous conditions. Gas readings show not just current levels but trends over time, which helps workers and supervisors spot rising hazards early and take action.

Keeping the record at the surface ensures it is readily accessible to all coal mine workers, across shifts, and it can be read easily by those who need to monitor conditions or verify compliance. This central, easily read record supports quick decision-making and proper communication about gas conditions.

Putting the record underground in a control room would limit access to specific personnel and could delay awareness; storing it in every crib room would be cumbersome and could lead to fragmentation or loss of data; keeping it in the mine library would not support timely, day-to-day monitoring.