A comparison of impedance measurement techniques in air.
James Thomas Mason · Defense Technical Information Center (DTIC) · 1984
The acoustic impedance of several Helmholtz resonators were measured using two different techniques. The first technique employed the conventional Standing Wave Tube method. The second was the Dual-Microphone Transfer Function of J. Y. Chung and D. A. Blaser. The calculability of the frequency dependent Helmholtz resonator impedance allowed the methods to be compared for both absolute accuracy and relative precision. The average relative precision for the SWT technique was 4.2% while the average for the dual-microphone technique was 18.4%. (Author)