What action must be performed to ensure the pressure gauges of a CO2 extinguisher indicate adequate pressure?

To ensure that the pressure gauges of a CO2 extinguisher indicate adequate pressure, the most effective action is to weigh the extinguisher. Weighing the extinguisher allows you to determine whether it contains the proper amount of carbon dioxide. CO2 extinguishers work by releasing compressed gas, and if the weight is below the manufacturer's specified weight for a full extinguisher, this indicates that some gas has been released and that the extinguisher may not operate effectively in an emergency.

While visual inspections, pressure testing, and temperature checks can provide useful information about the condition of an extinguisher, they do not give a definitive assessment of the contents. A visual inspection might reveal signs of damage or corrosion, but it won't confirm if there is sufficient gas. A pressure test checks the integrity of the extinguisher but does not indicate the amount of CO2 left inside. Similarly, temperature checks might inform you if the extinguisher is stored in an appropriate environment but do not assess the pressure directly. Therefore, weighing is the most reliable method to ensure the extinguisher is adequately charged for use.