What type of system is used to measure turbine engine exhaust gas temperature (EGT)?

The measurement of turbine engine exhaust gas temperature (EGT) is most commonly accomplished using a thermocouple system. Thermocouples are well-suited for this application due to their ability to withstand the high temperatures present in the exhaust stream. They operate on the principle of generating a voltage based on the temperature difference between two dissimilar metals joined together at one junction, which is exposed to the exhaust gases.

This capability allows thermocouples to provide accurate and rapid temperature readings, which are critical for monitoring engine performance and preventing overheating. The reliability and robustness of thermocouples make them the preferred choice in aerospace applications where extreme conditions are the norm.

Other options, while valid temperature measurement systems in different applications, are not typically used for measuring EGT in turbine engines. Resistive temperature devices (RTDs) offer high accuracy but are less durable under the extreme conditions found in exhaust systems. Bimetallic temperature gauges are more suited for lower temperature applications and are generally not used for high-temperature exhaust measurements. Infrared sensors can measure temperature from a distance but are not the standard for direct temperature measurements in turbine engines. Therefore, thermocouples stand out as the appropriate and effective method for EGT measurement.