🔍 Key Concepts

• flue gas analysis purpose in marine boilers and diesel engines • relationship between O2, CO2, and CO (carbon monoxide) in exhaust gases and combustion efficiency • how excess air or too little air affects combustion products

💭 Think About

• When you sample flue gas, what measurements are you actually taking (which gases)? • How would those gas readings help an engineer adjust the burner or engine for better performance? • Which of the choices is something you could realistically infer from exhaust gas composition, and which would require a separate lab test of the fuel itself?

✅ Before You Answer

• Identify which option directly relates to combustion efficiency and excess air control • Eliminate any options that would require testing the fuel, not the exhaust • Ask yourself: flue gas analyzers typically show O2, CO2, CO, and sometimes NOx – which choice matches what those numbers are used for?