Automated in-service test and evaluation of sonar hydrophones

Recent advances in microprocessor-based instrumentation permit rapid, precise, and detailed measurements on sonar transducers in the field. Reliable data combined with equivalent circuit models of the transducer provide information on acoustical sensor performance that can help to establish more realistic performance and maintenance criteria. This can substantially upgrade the quality of maintenance decisions made at the technician level in the field in light of the effects on well-understood parameters that relate directly to operational performance, such as sensitivity, array beam width, and bearing error, due to transducer degradation. Transducer complex admittance measurements made in-the-field using a commercially available computer controlled impedance meter will be described. Interpretation of the data and their relationship to the equivalent circuit model will be discussed and typical results will be presented. [Work supported by the Naval Sea Systems Command.]