Influence of feeder cable parameters upon accuracy in measurements of characteristics of powerful low-frequency underwater electroacoustic transducers

Providing required values of electro-acoustic parameters of low-frequency hydroacoustic transducers calls for precise measurement of their characteristics during tests. Using a long cable to connect an electric excitation system to a transducer without taking into account the electric characteristics of the cable leads on the one hand to measurement accuracy reduction, and on the other to non-optimal matching between the excitation system and the low-frequency transducer. This results in overall performance loss of the sound radiation system. Experimental studies of how a 1000 m long cable influences the results of measuring transducer electro-acoustic characteristics and its equivalent circuit parameters showed that resonance frequency and bandwidth measurement errors are insignificant in the frequency range up to 1 kHz, however the values of voltage and current at the excitation system output differ considerably from their values at the transducer input. When the cable influence is neglected, efficiency and sensitivity of the transducer are found to be underestimated in relation to their real values. The present study contains recommendations on the techniques of measurement and experimental data processing to compensate for the influence of the feeder cable on the measurement results. These recommendations are applicable to various metrological tasks of hydro- and electroacoustics, radio and electrical engineering, for arbitrary electrical loads in the audio and ultrasonic frequency range.