End correction for an open pipe from measured resonance frequencies Free

As briefly noted in freshman physics textbooks, resonance in open‐ended pipes depends on an effective length that is greater than the actual length of the tube. The additional end correction varies with the termination at the open end. By measuring several peak frequencies in a response function (pressure in the pipe over source excitation), we have calculated the end correction for open ends of PVC tubes of varying diameters with several flanges of increasing size. Temperature effects were carefully controlled, and resonance frequencies recorded to within 0.01 Hz. Averaged results are in agreement with literature and theoretical expectations, but anomalies and unexpected results will also be presented.