Pressure measurement for a wide range of applications

Seatools has a large experience base in the field of subsea pressure measurement. Pressure can be measured internally, such as in a submerged hydraulic system, as well as externally, for example to derive depth. Seatools’ standardized subsea pressure sensor range Pressit® represents a highly accurate sensor range, which is characterized by a robust design and is extensively used in harsh dredging and subsea environments. Our highly accurate applications form an excellent basis for subsea monitoring and control systems, as is demonstrated by the strongly diverse subsea (installation) monitoring systems Seatools has delivered in the past.

Length, displacement, and position measurement

Seatools has extensive experience with, and offers a wide range of sensors and monitoring systems for, subsea length, displacement (i.e. stroke), and position measurement. For 1D underwater displacement measurement, Seatools offers the WLM Wire Length Measurement sensors as well as linear stroke sensors, which are both highly robust and accurate. For (relative) position measurement in up to all 3 dimensions, our ‘HighWire’ taut wire system offers unprecedented accuracy, high update rates, and excellent reliability in a wide variety of circumstances. In addition to the above-mentioned standardized sensors and systems, Seatools has shown its expertise in the integration of sensors, using alternative principles – such as acoustics (e.g. Doppler, USBL) – to measure the position of submerged objects.

Level and volume measurement

Seatools offers a variety of solutions for level and volume measurement in subsea applications, such as for subsea compensators and reservoirs. In essence, two types of systems exist: point level measurement systems and continuous level measurement systems. Seatools delivers point level measurement systems based on its Proxis® subsea proximity sensors. These systems provide an (alarm) signal once a pre-specified (fluid) level (e.g. low level or overfill) has been reached. Rather than measuring a single point, continuous level measurement solutions measure fluid levels across a range, producing a signal positively correlated to the actual fluid level. All of Seatools’ sensors are highly accurate and were built to withstand the harshest of offshore conditions.

Accurate subsea inclination and angle measurement

Seatools is highly experienced in both inclination and angle measurement in offshore and subsea environments. This experience ranges from straightforward winch angular position measurement to inclination measurement of pontoons and large structures (such as jackets during the jacket upending process). Depending on your specific application, a variety of field-proven, standardized subsea sensors can be applied, such as the rotation sensor range or the inclinometer sensor range. In addition, Seatools has supplied a variety of custom-built inclination measurement systems over the years. The (template) leveling system, for example, allows for very efficient and accurate leveling operations of large structures. Also the wireless level measurement system has provided clients with unprecedented accuracy.

Angular and linear motion measurement

Throughout the years Seatools has acquired extensive expertise in (linear & angular) motion measurement and processing of offshore and subsea equipment. This knowledge base has been acquired first of all during the development of subsea DP systems, applied to many of our fall pipe ROVs. Secondly, Seatools’ experience stems from the development of a wide range of heave and motion compensation systems in which motion measurement and processing has a significant influence on compensation accuracy. Thanks to these developments, an extensive library of motion sensor behavior (including sensor-specific imperfections) was developed, put to use during simulations reproducing sensor performance (incl. noise and update rate) and data transmissions (incl. delays). As a result, the performance of the entire (monitoring and/or control) system can be analyzed and verified.

Force and torque monitoring and control

Seatools delivers highly accurate force and torque monitoring and control systems for subsea equipment. Accurate force and torque measurement and control is of utmost importance to a wide range of subsea operations, for example to prevent wire overload in diamond wire saws. For the Barracuda subsea diamond wire saw, for example, Seatools developed a highly accurate saw control system as part of the all-electric subsea drive system. In this case, the incorporation of load cells facilitated highly accurate tension measurement. At other times, Seatools applied load cells to measure parameters such as umbilical loads, seabed contact forces, towing forces, and winch torques. To view an example, please refer to the survey ROV of the Rockpiper ROV.

Density and (mass / volume) flow measurement

Partially thanks to Seatools’ expertise in dredging and subsea excavation (equipment), Seatools houses considerable knowledge of subsea density and flow measurement. Flow measurement is available for hydraulic oil flow in subsea hydraulic systems, water volume flow in e.g. ballast monitoring systems, and mixture flow in dredging monitoring systems. In addition, Seatools is experienced in subsea density measurement technologies based on non-radioactive methods. When combined with fluid velocity measurement, these technologies can provide accurate dredging production data with regards to mass flow. It makes for a unique measurement technology that is particularly beneficial to subsea excavation equipment as it enables slurry density optimization and boosts productivity as a result.

Internal and external subsea temperature measurements

Seatools offers a variety of solutions for subsea temperature measurement. Our subsea temperature measurement systems can be internal, to measure oil temperature in a hydraulic system or component, or external, to measure the temperature of local seawater.

Current, voltage, resistance, and frequency measurement

Because of its background in the development of subsea equipment such as ROVs, Seatools has a large experience base in the measurement of electric quantities such as electric current, voltage, insulation resistance, and frequency. In virtually all of Seatools’ subsea equipment delivered, insulation resistance measurement of components such as powerpacks, umbilicals, and electronics is incorporated. In order to monitor the condition of cathodic protection of ROVs, previous deliveries have also included CP probes.

Vibration, magnetic flux, water detection, sound, and other

Above and beyond the previously mentioned list of physical parameters, Seatools is also experienced in the areas of measuring and detecting:

• vibration
• acceleration
• rotational speed
• magnetic flux
• water in oil
• sound
• heading
• light level
• ambient pressure
• depth
• altitude

Please contact our sales department to discuss the parameters you intend to measure and/or control, and we will gladly assist you in your inquiry.

Accurate positional data under harsh conditions

The HighWire is a robust taut wire system for offshore and submerged operations. The system can be applied in operations that require accurate and real-time positional data of submerged objects, such as during pile driving, mudmat or caisson installation, spool piece installation, and marine civil engineering projects.

Key features:

• Unprecedented measurement accuracy
• Operable in any environment: above surface, subsea, splash zone, or mixed
• Unaffected by noise

READ MORE