Choosing Relays for Underwater Acoustic Systems

When selecting relays for underwater acoustic systems is vital to prioritize environmental durability and signal integrity. Submerged systems face relentless pressure, saline exposure, and continuous wetting, so the relay needs a hermetic seal with corrosion-resistant construction using stainless steel or advanced polymers. Typical commercial relays cannot withstand prolonged submersion.

The relay must also handle the low voltage and low current signals typical of acoustic transducers and sensors without adding interference or degrading signal quality. SSRs are typically the optimal choice compared to electromechanical relays because they have no moving parts, which increases reliability and reduces the risk of failure due to vibration or pressure changes. Their silent operation prevents EMI that might corrupt delicate underwater acoustic data.

Equally important is the device’s thermal performance range because systems encounter extreme thermal gradients—from freezing abyssal zones to tropical surface layers. Performance must remain stable across the entire operational thermal window. Choose relays certified for -40°C to +85°C operation, ideal for marine use.

Low power draw is critical, especially for autonomous, long-duration submersibles. A low coil current requirement and minimal power loss during operation will maximize deployment duration and minimize servicing.

Finally, consider the switching speed and contact life. Many applications demand high-frequency switching to steer acoustic beams or route signal paths. One rated for extended endurance and rapid actuation ensures consistent performance over the system’s operational lifetime. Demand documented proof of submersible certification and insist on environmental stress test results under real-world underwater parameters. Selecting an appropriate relay is a matter of mission-critical reliability in Earth’s most hostile aquatic domains.