What is the role of a fire extinguisher's pressure gauge?

The pressure gauge on a fire extinguisher serves a vital function by indicating whether the extinguisher is properly charged. When the gauge needle falls within the green zone, it signifies that the extinguisher is filled to the correct pressure, making it operational and effective in the event of a fire. If the needle points to the red zone, either undercharged or overcharged, it indicates that the extinguisher may not work properly when needed, thereby compromising safety.

Understanding the pressure gauge is crucial for ensuring readiness in emergencies. Regular checks ensure that the extinguisher is not only charged but also maintained in compliance with safety standards. This functionality sets the pressure gauge apart from other components, such as the manufacturer date or aiming indicators, which do not directly relate to the operational readiness of the extinguisher in terms of pressure.