🔍 Key Concepts

• Thermocouple – what it measures and where it is usually placed on diesel engines • Typical methods of monitoring exhaust temperature vs. cooling water, fuel, and lube oil • Why engineers watch temperature at multiple points on a large main propulsion diesel

💭 Think About

• Ask yourself: which of these four fluids or gases would most benefit from having multiple temperature readings at different cylinders or locations? • Think about what abnormal temperature patterns (too hot or one unit hotter than others) can tell you about engine performance or combustion problems. • Which system usually already has dedicated pressure/temperature gauges and doesn’t typically need many separate thermocouple probes on every unit?

✅ Before You Answer

• Verify what a pyrometer is normally used for in marine diesel practice. • Check which of the listed options would logically have sensors at various locations rather than just one or two points. • Confirm which system’s temperature is a primary indicator of combustion quality and engine loading on each cylinder.