Resonant reciprocity calibration of conventional, magnetohydrodynamic, and quantumfluidic transducers

Since its application to transducer calibration in 1940 by Cook and MacLean, the reciprocity method has been used for absolute calibration of electroacoustic transducers in a relatively limited number of geometries and media. Following Prof. Rudnick's article on extensions of this technique to unusual geometries [J. Acoust. Soc. Am. 63, 1923 (1978)], the resonant reciprocity technique to high‐precision (noncompliant) microphone and hydrophone calibration in air and water, to magnetohydrodynamic (ultracompliant) transducers in salt water and mercury, and to thermomechanical (second sound) transducers in superfluid ⁴He has been applied. The technique for generalization of the theory to conducting and quantum fluids along with the experimental apparatus used to verify the generalizations will be described. [Work supported by the ONR.]