What is the purpose of the peak reading on a gas detector?

The peak reading on a gas detector is designed specifically to show the highest level of gas concentration that has been recorded by the device during a given period. This feature is crucial for safety in mining operations, as it allows personnel to understand the maximum exposure level to hazardous gases, which can be vital for making informed decisions about venting, evacuation, or other safety measures. By identifying the peak concentration, mine foremen and safety personnel can assess whether conditions are becoming more hazardous and take appropriate action to protect workers' safety.

The other options do not encapsulate the primary role of the peak reading. While measuring current gas levels is part of the gas detector's function, it does not provide the critical historical context that peak readings do. Indicating sensor performance might be relevant, but it does not specifically pertain to the peak reading feature. Additionally, peak readings do not reset the sensor alarm; instead, they provide a record that helps in evaluating safety measures.