What is the significance of checking the pressure readings before using a BG4?

Checking the pressure readings before using a BG4 is crucial to ensure full operational functionality. The BG4 is a breathing apparatus used in mine rescue situations, and proper pressure levels are essential for the device to supply an adequate and safe air supply to the user. If the pressure is not within the required range, it could indicate that the apparatus is either not filled properly or may have a leak, potentially putting the user at risk during a rescue operation. Ensuring that the device operates as intended allows rescuers to focus on their mission without worrying about the reliability of their equipment.

The other options, while they touch on important safety and functionality aspects, do not encapsulate the primary reason for checking pressure readings in the context of operational readiness and safety during emergency situations.