What is the purpose of the pressure gauge on a fire exthinguisher?

The pressure gauge on a fire extinguisher indicates whether the extinguisher is properly pressurized and ready for use. It typically features a color-coded dial, showing whether the pressure is within the optimal range. If the needle is in the green zone, the extinguisher is functional; if it's in the red zone, the extinguisher may be under- or over-pressurized and requires maintenance. Regularly checking the gauge ensures the extinguisher will operate effectively in an emergency.