Transfer function characterization of pressure signal tubes for the measurement of large amplitude pressure fluctuations

Abstract

Abstract

The measurement of fluctuating pressures in gasses is relevant to a wide range of fluid flow applications. The frequency response of pressure measurement systems using remote transducers is usually limited by the response of the connecting tubing. For small fluctuation levels it is well established that the signal distortion can be corrected using a transfer function technique. This work extends the approach to include the more challenging issue of large amplitude fluctuations where the transfer function is strongly dependent on the fluctuation amplitude as well as frequency.

The tubing transfer function was found to closely depend on the ratio of the standard deviation of the pressure fluctuation and the absolute pressure (P _STD/P _ABS). An algorithm for correction is described and demonstrated. Levels of P _STD/P _ABS of up to 0.6 have been tested and distortions of up to 250 per cent have been corrected to within 5 per cent.