EGT (aviation)

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EGT indicator

EGT (for exhaust gas temperature , dtsch. Exhaust temperature ) the measured temperature is the exhaust gas of a piston engine or a gas turbine .

Measurement

The sensor usually is a thermocouple type K consisting of a transition between a nickel - chromium - alloy and nickel. Semiconductor sensors or PT100 resistance thermometers are unsuitable for the high temperatures that occur, or they are unsuitable for providing the required long operating times of several thousand hours. The thermocouple is connected to suitable special cables so that the measuring voltage is not falsified by further transitions at connections between different metals.

Engine control

In a piston engine, tendencies towards overcooling or overheating due to the enrichment or emaciation of the fuel-air mixture can be detected early on by measuring and displaying the exhaust gas temperature. With the help of EGT, the engine can be leaned to such an extent that the engine is not damaged, and fuel consumption is reduced at the same time. A detailed description of the process can be found under Leanen .

With jet engines , temperatures are measured at several points and displayed on the one hand, but also used to control the engine on the other. The difference between exhaust gas temperature and outside temperature essentially determines the efficiency of the engine. The maximum possible exhaust gas temperature is determined by the heat resistance of the materials of the first turbine stage. High-quality ceramic materials or nickel alloys are therefore used for the cooled turbine blades of this stage. The exhaust gas temperature is mostly measured behind the turbine, but with turboprop engines there is also a display for the turbine inlet temperature (TIT), or a display for the temperature inside the turbine (ITT).

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