Gas examinations in active face areas must be performed at least every 20 minutes. What time unit is used for this interval?

Gas examinations in active face areas must be performed at least every 20 minutes. What time unit is used for this interval?

• A. Hours
• B. Seconds
• C. Minutes
• D. Days

Answer: (C)

Gas checks in active face areas are about monitoring for dangerous gases as the face advances, so the interval is expressed in a short, practical unit. The rule specifies a check at least every 20 minutes, making minutes the natural time unit. If we used seconds, it would imply checks every 20 seconds, which is far more frequent than typical operations. Hours or days would be far too long and could miss rapid changes in gas levels, compromising safety. Using minutes appropriately matches the pace of the work and the need to detect gas changes in a timely way.

Gas checks in active face areas are about monitoring for dangerous gases as the face advances, so the interval is expressed in a short, practical unit. The rule specifies a check at least every 20 minutes, making minutes the natural time unit. If we used seconds, it would imply checks every 20 seconds, which is far more frequent than typical operations. Hours or days would be far too long and could miss rapid changes in gas levels, compromising safety. Using minutes appropriately matches the pace of the work and the need to detect gas changes in a timely way.