Aquatic and Underwater Use of Pressure Sensors

Pressure sensors are crucial to ensuring the safe functioning of logistic equipment in a wide range of underwater applications. For scuba diving, an operational depth gauge or diving watch is essential when estimating diving depth and ensuring the ascent and descent are safely performed. 

Historically, the majority of dive watches and depth gauges have been analog by design. Digital pressure sensors have a number of significant advantages over analog sensors and have the capacity to be interfaced with dive computers that can combine information from several sensors at the same time.A digital pressure sensor includes a sensing element; for pressure sensors, this is typically a piezoresistive element and a transducer to transform the sensor response into a digital signal for processing.

Digital sensors can be extremely compact, with no moving parts and can be put to use in unforgiving, corrosive environments, such as salt water. Piezoresistive sensors are well-adapted for taking aquatic measurements as they have hardly any restrictions on their operating depths.These pressure sensors commonly find application in dive watches, sonar buoys, sometimes known as sonobuoys, tank and ocean depth measurements, and the fishing industry.

Merit Sensor Systems

Merit Sensor Systems leads the way when it comes to developing pressure sensors for many different applications, including diving and freshwater work. Merit Sensor Systems can provide a number of different sensing devices with exceptionally small footprints and ultra-low power draw.

Low power consumption is crucial in remote aquatic applications as devices require a battery that can last for a prolonged period.

For sonar buoys, mobile devices that use sonar signals are deployed to locate passing submarines and marine traffic, as well as to monitor tidal conditions, Merit Sensor Systems has designed a series of pressure sensors that can replace conventional wired technology.

Normally, when deployed, a buoy would be tethered using a spool of wire connecting the device to a float at the surface, and the length of the wire is used to calculate the depth of the device.

However, due to the fact the ocean is in constant flux, the wire displacement can be a poor measure of the depth due to lateral deflections of the device when submerged in water. A digital pressure sensor can offer more accurate depth measurements by measuring the local water pressure.

For sonar buoys, Merit Sensor Systems has a range of suitable sensors on offer, including the HTS 1510 Series, the TR series, and, for more restricted operating depths, the ultra-low power MS series.

All of these sensors are extremely compact and lightweight, meaning they can be easily incorporated into an extensive range of devices while offering hours of continuous operation. The HTS series will also have a Sleep mode built-in in the near future so that the battery life can be preserved for longer.

Each Merit Sensor System is now media compatible in a wide range of water environments and conditions. The MS series is gel-filled for extra protection, and its compact footprint means it can be incorporated into dive watches.