High Tech, Inc. Hydrophones

Over 200,000 units have been manufactured and deployed with excellent results in government and industry applications. The hydrophone/preamplifier assembly consists of piezoelectric ceramic cylinders which form the hydrophone active acoustic element. The preamplifier is mounted inside the ceramic cylinder and interfaces the active element to the signal conditioning electronics via an underwater connector.

Each model features an integral Faraday shield for EMI rejection and improved crosstalk performance. The ceramic cylinders are radially polarized MIL-C-1375 Type I material. With end caps, the enclosed cylinder forms a small pressure vessel which houses the preamplifier assembly. This "air backed" design is capable of withstanding pressures to 10,000 psi.

The preamplifier itself is a transconductance amplifier design which eliminates the need for separate power and signal conductors. Preamplifier power consumption is less than 48 mW based upon 12 VDC. Conventional 3-wire voltage mode amplifiers are also available. Completed assemblies are encapsulated in polyurethane and pressure cycled to operating depth prior to calibration.