Which step is included in purging the sampling equipment?

• A. Purge the sample tube and purge the sample bag
• B. Do not purge anything
• C. Inflate the bag
• D. Roll the bag diagonally to seal

Answer: (A)

Preparing sampling equipment to avoid contamination and ensure representative results is what this item tests. Purging the sample tube and the sample bag removes any residual gas or contaminants from previous samples, so the path the current sample travels is clean. This helps the measured gas composition reflect the actual sample rather than lingering leftovers, which is essential for accuracy and safety in mine sampling procedures. At the same time, simply not purging would leave old gas in the line and bag, skewing results. Purging the bag isn’t just inflating it; inflating would introduce air or other gases and isn’t the cleansing step. Rolling or sealing methods aren’t about clearing residues; they’re about containment, not purification. So purging both the tube and the bag is the correct, best practice.