What is the purpose of temperature sensors (thermocouples) in turbine instrumentation?

• A. Measure ambient air temperature only
• B. Measure critical temperatures (ITT/EGT) to monitor operation and protect components from overheating
• C. Measure oil viscosity
• D. Provide audio alarms

Answer: (B)

Temperature sensing in turbine instrumentation is about keeping a real-time picture of how hot the engine is in its critical areas. Thermocouples placed in the hot sections feed temperature data to the control and protection systems so the engine can stay within safe limits. By monitoring critical temperatures like ITT (inter-turbine temperature) or EGT (exhaust gas temperature), the system can trim fuel, adjust airflow, or shut down the engine if temperatures threaten components. This is essential to prevent overheating and damage to turbines, combustion liners, and blades.

Ambient air temperature isn’t the primary concern for turbine protection, and oil temperature sensors exist for lubrication systems but aren’t about measuring viscosity themselves. Audio alarms are just a way the readings are communicated, not the fundamental purpose of the sensors.