A pyrometer indicating system such as that...

🔍 Key Concepts

• Thermocouples vs. Resistance Temperature Detectors (RTDs) – how each generates or uses electrical signals when heated • Self-powered vs. externally powered sensors – which devices need an outside power source to create a readable signal • Typical instruments for exhaust gas temperature indication on diesel engines

💭 Think About

• Think about which device creates a small voltage on its own when two different metals are joined and heated, and which one only changes resistance when powered from an external circuit • Ask yourself: for high-temperature exhaust gas measurements, which sensor type is most commonly used on large diesel engines? • Consider whether a pyrometer needs an external power supply at the sensing junction itself, or only at the indicator/instrument side

✅ Before You Answer

• Recall that RTDs (resistance temperature detectors) work by changing electrical resistance and typically need an external current to measure that change • Recall that thermocouples produce a millivolt signal from temperature difference between two dissimilar metals and are often described as self-generating • Match the idea of a traditional diesel exhaust pyrometer probe to the correct sensor type and whether it’s considered self-powered or externally powered at the sensing element

A pyrometer indicating system such as that used for measuring diesel engine exhaust system temperatures uses what technology?

externally-powered thermocouples

externally powered resistance temperature detectors

self-powered resistance temperature detectors

self-powered thermocouples

🔍 Key Concepts

💭 Think About

✅ Before You Answer