ABSOLUTE CALIBRATION OF ELECTROACOUSTIC TRANSDUCERS BY THE RECIPROCITY METHOD IN A QUASI-SPHERICAL FIELD (ABSOLYUTNAYA GRADUIROVKA ELEK PREOBRAZOVATELEI METODOM VZAIMNOSTI V KVAZISFERICHESKOM POLE),

摘要

The calibration of electroacoustic transducers with respect to a field involves the pressure in a free plane wave. In actual practice,however,the calibration is always produced in a quasi-spherical field of real transducers. The results give,within a certain degree of accuracy,the desired value of the sensitivity of the transducer for both reception and transmission. Of course, a sufficiently detailed examination of the conditions of the calibration should be made before the practical measurements are carried out. The theory of the reciprocity method of absolute calibration of electroacoustic transducers in a spherical wave has been examined in a series of articles. Nonetheless,the theory has not been complete until now. The fundamental deficiency of the theory as it appears in the literature is the failure to take into account all of the conditions of measurement,particularly the mutual effect of the finite dimensions of the participating transducers on each other,and the difference between the actual conditions of calibration in a spherical wave and the ideal conditions for a free plane-wave field.