Pressure waves in the combustion chamber are led to the sensors, which are located outside the
central casing, via narrow tubes (measurement part). Additional tubing is used beyond the sensor to
absorb pressure waves travelling through the pipe (acoustic resonance damping part). The air supply
feeds the measurement device with air from the compressor in order to avoid condensation in the
pipe system and to achieve a smoother temperature gradient in the pipe from the transducer to the
outer liner of the combustion chamber.