Title :
A low-density extended acoustic sensor for low-frequency arrays
Author_Institution :
Focas Ltd., Swindon, UK
fDate :
10/1/1988 12:00:00 AM
Abstract :
A novel PVDF hydrophone is described which has a sensitivity of -183 dBV/μPa or better and can be made in lengths from 4 cm to more than 1 m, and in diameters from 8 mm to >40 mm. It is based on a piezoelectric PVDF cable which allows considerable design freedom because of its very great mechanical flexibility and high longitudinal piezoelectric coefficient. The design centres on a helical structure which translates a hydrostatic pressure field into a longitudinal compressive strain in the cable and thus makes use of the very sensitive mode. Excellent pressure stability can be achieved, with devices showing a pressure dependency of 0.04 dB/MPa. The device has a flat frequency response from less than 1 Hz to several kHz and a density in the region of 1800 kg/m3, making it suitable for application in low-frequency sonar
Keywords :
hydrophones; 1 Hz to 1 kHz; PVDF hydrophone; frequency response; helical structure; hydrostatic pressure field; longitudinal compressive strain; low-density extended acoustic sensor; low-frequency arrays; mechanical flexibility; piezoelectric; sonar; Acoustic arrays; Acoustic sensors; Ceramics; Coaxial cables; Manufacturing processes; Polymers; Sensor arrays; Sonar applications; Sonar equipment; Stability;
Journal_Title :
Oceanic Engineering, IEEE Journal of
