At what oxygen level is the alarm on a gas detection meter typically set to activate?

The alarm on a gas detection meter is typically set to activate at an oxygen level of 19.5%. This threshold is significant because it represents the minimum acceptable oxygen concentration for safe breathing in a work environment. In the workplace, an oxygen level below 19.5% can lead to symptoms of oxygen deficiency, such as dizziness, unconsciousness, or even suffocation. Therefore, the 19.5% threshold is established as a safety standard to warn workers when oxygen levels drop to potentially hazardous conditions. This ensures that adequate measures can be taken to restore safe oxygen levels and protect personnel from the risks associated with oxygen deficiency.