A fire extinguisher guage is one of the several ways to check the condition of a fire extinguisher as it displays the pressure of the fire extinguisher content. It is a helpful indicator that a unit has not been used or damaged and is in proper working condition. Most fire extinguishers have a guage on them, apart from CO2 fire extinguishers, which cannot be tested by measuring the pressure and must be weighed for CO2 content instead. How to Read a Fire Extinguisher Guage Fire extinguisher guage displays are divided into three regions/zones; the recharge zone, the green zone in the middle and the overcharged zone. To conduct a fire extinguisher guage check, take a look at where the fire extinguisher guage indicator is pointing. Each zone indicates the following: 1. Recharge zone Is the fire extinguisher guage in the red and pointing to the left, this is the “recharge” zone. It means the fire extinguisher has either been used or that pressure has leaked from the cyclinder. An undercharged unit lacks the pressure neccessary to propel the fire suppressant. Inform your fire expert to have the cyclinder refilled immediately. 2. Green zone A fire extinguisher whose needle is pointing in the green zone means that the fire extinguisher is correctly charged and is ready to suppress fire once used. The needle should point right in the middle of the guage. 3. Overcharged zone If the needle is pointing to the red zone on the extreme right, it means that the fire extinguisher contents are under too much pressure. An overcharged fire extinguisher unit can cause a leakage or worse, a cyclinder explosion. Immediately contact your fire expert to have it normalised.