Which pressure range corresponds to the function of the pressure relief valve in a BG4 system?

The function of the pressure relief valve in a BG4 system is critical for ensuring the safety and proper functioning of the breathing apparatus. In a BG4 system, the pressure relief valve is designed to open and release excess pressure when the internal pressure exceeds a specific threshold.

The correct pressure range of 2 - 5 mbar aligns with standard operational parameters for these systems. This range ensures that the valve activates at a pressure high enough to prevent over-pressurization that could damage the device or hinder its effectiveness, while also being low enough to allow for the proper functioning of the breathing apparatus during its use.

When considering the other options, they either fall below or exceed the necessary operational parameters for the pressure relief function. A range such as 1 - 3 mbar might not adequately manage the necessary pressure regulation, while options like 5 - 8 mbar are too high, potentially posing a risk of over-pressurization unaddressed by the valve. The range of 1 - 2 mbar similarly does not provide sufficient safety margin, reinforcing why 2 - 5 mbar is recognized as the appropriate specification for effective pressure management in the BG4 system.