Measurement of Cylinder Diameter by means of Sound Signal. Measurement by Phase Delay of Plane Waves.
Masanao Yamada, Ryoichi ICHIMIYA · TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C · 1992
A new measuring method of a cylinder diameter by means of sound waves is described in this paper. The method is based on the phenomenon that the phases of sound waves scattered by a cylinder are delayed according to the diameter of the cylinder. Experiments were performed in the diameter range from 40 to 100 mm using 500- or 2500-Hz pure tone signal. Results showed that the phase. delay was linearly proportional to the cylinder diameter over a wide diameter range. The experimental results were compared with the theoretical results obtained by analyzing the problem of disturbance of plane waves by a cylinder. Agreement between the experimental and theoretical results was good. It was also found that reflections from walls and from a radiator increased the rate of change in phase delay with diameter. As a result, the utilization of reflections seems to be one method available for improvement in accuracy of this method.