Which is a provision included in SOP for methane detector failures on vehicles?

The provision stating that a portable methane detector must be used is correct because it aligns with safety protocols aimed at ensuring the health and safety of workers in mines, particularly regarding the management of hazardous atmospheres. Methane is a colorless, odorless gas that can accumulate in mining environments and poses significant risks, including the potential for explosions or asphyxiation.

In the event of a methane detector failure, having a portable methane detector serves as an alternative measure to continuously monitor for the presence of methane in the atmosphere. This ensures ongoing safety checks are in place until the main detection system can be repaired or recalibrated. Utilizing portable detectors provides immediate feedback and can help in taking prompt actions to mitigate risks associated with methane buildup.

In contrast, the other options do not adequately address the necessary safety protocols. Allowing the machine to continue as usual could lead to dangerous situations if methane levels are elevated and undetected. Monitoring just once daily does not provide enough vigilance in a potentially hazardous environment where conditions can change rapidly. Measuring gas concentration only every shift might not capture fluctuations in methane levels, which makes continuous monitoring crucial for safety. Thus, the use of portable methane detectors is a vital provision that ensures a proactive approach to managing methane risks in mining operations.