🔍 Key Concepts

• Fuel oil burner operation and how flame stability is maintained • Meaning of pressure range over which a burner can operate while still maintaining ignition • Difference between ratio related to control range versus ratio related to mixture quality (air vs fuel)

💭 Think About

• Ask yourself: Which term describes how wide a burner can be adjusted (in terms of fuel pressure) and still keep the flame lit? • Which options refer to the quality or proportion of the combustion mixture rather than the operating range? • Which engineering term is commonly used to express the maximum controllable output divided by the minimum stable output of a burner or boiler?

✅ Before You Answer

• Identify which choice refers specifically to a range of stable operation for the burner, not just combustion efficiency. • Eliminate any term that clearly focuses on the proportion of air to fuel rather than the operating span of fuel pressure. • Think about boiler/burner design: what term describes how much you can turn the burner up or down while still having a stable flame?