🔍 Key Concepts

• CO2 fire extinguisher maintenance standards and required recharge criteria • Difference between weight of charge and weight of full bottle (bottle + charge) • Why small losses in extinguishing agent mass are critical for system effectiveness

💭 Think About

• Focus on whether the regulation is concerned with the gas inside only, or the cylinder plus gas together—what is actually doing the firefighting? • Think about typical allowed tolerance in safety‑critical systems: is a 20% loss usually acceptable for something you may rely on only once in an emergency? • Ask yourself: which option best reflects a conservative safety margin while still allowing for normal minor loss or scale inaccuracy?

✅ Before You Answer

• Identify whether the threshold is based on weight of charge only or full bottle weight • Consider typical inspection practice: do technicians compare the current weight to the stamped charge weight or to the gross full weight? • Eliminate any option that seems too high a loss for a life‑saving fire protection system.