A new measuring method of displacement and position by means of variation of sound frequency of air column in a small pipe. (Relationship between active end correction and transit angle).

Abstract

This paper deals with the development and analysis of a new method of measuring displacement and position by means of the variations of the sound frequency and the air column in a resonant pipe. Sound generates when compressed air is blown across an open-ended face of a small pipe. The sound frequency varies with the length of the air column in the resonant pipe. By applying this phenomena, a new, accurate and simple method for measuring the displacement and position is examined and developed. The displacement corresponds to the length of the air column and the variation of the sound frequency shows a close relationship with the displacement. The resonant frequency of the pipe can be shown by a simple equation; however, the resonant frequency does not coincide with the sounding frequency of the pipe. The difference between these two frequencies is explained in this paper as active end correction of the pipe.