Probe Reversal and Pressure Based Bias Error Correction Procedures Applied to Intensity Measurements in Planar Standing Waves

Abstract

An analytical application of probe reversal and pressure correction strategies to minimize channel phase errors in P-P intensity measurements within discrete frequency standing waves is made. Two potential error sources, error of position upon reversal and error of pressure correction, are examined and found negligible at low frequencies but likely to be problematic at high frequencies. It is predicted that pressure correction or probe reversal can lead to superior performance when compared with measures without correction at modest and higher standing wave ratios in true intensity assessment; the frequency range for a given probe spacing is also extended. The correction procedures are then applied to low frequency measurements (63 Hz and 125 Hz) for a range of standing wave ratios. It is found that correction procedures generally lead to better results than uncorrected measures, but beyond a standing wave ratio of about 30 dB at 63 Hz additional error source arises which renders inaccurate the result of correction procedures, particularly for smaller probe spacing measures.