Practical acoustic thermometry: a new way to measure reactor temps?
Figure 2: Qualitative illustration of the ‘pulse-shape problem’. Feeding an electrical pulse into a loudspeaker typically results in an initial acoustic pulse with an oscillating ‘tail’ due to ‘ringing’ at even modest sound pressure levels. After travelling through the tube, the acoustic pulse is modified, making timing measurements difficult. Surprisingly this problem can be tackled by the use of ‘chirps’ (inset) and some complex mathematics.