Developing Subsea Inclinometer Sensors for Underwater Surveying

SUBSEA2 inclinometer Tarka diver with SUBSEA 2 inclinometer


TARKA-SYSTEMS is an innovative company specialized in the development and production of client-specific measurement and monitoring tools and (portable) data-acquisition systems (hardware and software). The company TARKA-SYSTEMS was founded after 15 years world-wide field experience and system development for one of the largest maritime research institutes in the world.

The Application

Tarka-SYSTEMS design and manufacture specialist measurement equipment for marine, offshore, salvage and civil engineering applications. Their MOSS system is used for underwater surveying projects; it features inputs for two water depth sensors and an inclinometer sensor.

The water depth sensors measure: 1) the distance from the water surface and 2) the distance from the Amsterdam Ordnance Datum, which is a commonly used measurement in western Europe. The depth and tilt readings are displayed on the MOSS screen while also saving onto a USB. Tarka-SYSTEMS plans to use the MOSS system and SUBSEA inclinometer for several projects in the future but have two customers who needed it quickly.

The first customer needs to measure the alignment of underwater GEWI anchor piles, which are foundations made from steel and grout. The second customer will check for tilting or bending of man-made “sheet pile” walls, such as those used in ports and docks; these results will be used to decide if maintenance is needed to prevent damage.

The Challenge

For these harsh underwater conditions, the sensor needs to be robust while also remaining lightweight enough to comfortably carry alongside diving equipment. Using a normal inclinometer in these conditions is not possible without using an additional pressure-tested enclosure around the sensor, which adds a large amount of size, weight, time, and cost to the project. Some sensors are already available in waterproof enclosures, but these are much larger and heavier, which makes them less practical for diving because standard inclinometers on the market would not accommodate these requirements, and the range of products we had at Level Developments did not contain all the necessary specifications.

After discussing the application with Tarka-SYSTEMS, we knew exactly what specifications to introduce to our current range, along with the design and manufacturing innovation needed to bring this product to market in a timely manner.

The Solution

After a rapid design and manufacturing phase to adapt our current range of precision inclinometers, we introduced the SUBSEA-2 inclinometer series – high-performance dual-axis inclinometers specifically designed to be submersible for installation on underwater structures and marine equipment. Thanks to the innovative, robust, and compact design of the stainless-steel housing, the SUBSEA-2 sensors are small and lightweight enough to be used comfortably underwater, whilst also being capable of withstanding harsh treatment. They also feature impressive accuracy specifications and an industry standard SubConn Micro connector, which made integration with the MOSS system extremely straightforward.

The sensor’s enclosure is conservatively rated for 500 m depth in water, but has already been tested up to 100 bar pressure (~1000m depth). They measure angle in both pitch and roll axes, with standard measurement range options of ±5°, ±15°, ±30° and ±45°. Like many of our inclinometer sensors, they utilise a very high-performance MEMS sensor that exhibits low long-term drift and excellent temperature stability when compared with competitive devices.

The Benefit

This solution has enabled Tarka-SYSTEMS to meet both of their customers’ immediate requirements while also adding further potential and value to their existing MOSS system, meaning it can be used in an even wider variety of surveying and monitoring applications in the future.

Furthermore, we at Level Developments are confident in providing future service to Tarka-SYSTEMS, alongside any technical and application support for this product.

Visit our SUBSEA-2 subsea inclinometer product pages for more information on individual specifications, certifications, and datasheet information.

“Working with Level Developments gave us the right solutions for our project requests from our clients, and with the quality of the product and the professional people behind it, we look forward to a very good cooperation in the future.”