MRU Subsea

The NORSUB MRU SUBSEA is an ideal choice for accurate and robust subsea motion measurements. With a depth rating of up to 6000 meters, this compact and small-sized motion sensor offers versatility in installation.

MRU Subsea

Product overview

The MRU Subsea can be easily placed in various locations due to its small size and footprint. Communication options include ethernet, RS-232, and RS-485/422, while power and communication are facilitated through the Subconn connector.

For enhanced functionality, the Subsea MRU can be equipped with a high-end magnetometer, ensuring precise magnetic heading measurements.

The Subsea MRU is available in three versions, 3000, 6000, and 9000, to cater for different accuracy requirements and budgets.

Additionally, the Subsea MRU is offered in an inclinometer version that focuses on continuous monitoring of the roll/pitch angle of subsea templates at a lower cost. This eliminates the need for expensive subsea rentals during installation.

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High Accuracy

High accuracy roll, pitch and heave, even in irregular sea states.

Compact Size

Low weight and small footprint make installation and handling easy.

Depth rated to 6000 M

Depth rating at 6000 m enables motion measurements in ultra deep waters.

Specifications

Download product brochure

Casing

Environment

6000 m water depth

Casing material

Titanium

Dimensions

76 mm x 76 mm x 165 mm

Weight

1.2 kg

Interfacing

Connector

SubConn 8-pin FCR1508M

Ports

Ethernet & RS-232, Ethernet & 2-wire RS-485

Communication

TCP, UDP, Modbus TCP, ethernet/IP

Output frequency

0-100 Hz

Performance

Roll & Pitch

3000 series: 0.05°
6000 series: 0.02°
9000 series: 0.01°
RMS (dynamic & static)

Heave (real-time)

5.0 cm or 5.0 %
Whichever is greater for 0 to 25 s periods, valid for irregular motions in real sea conditions

Heading (optional)

± 0.5 °
Magnetic heading

Range

Rotation speed

3000 series: ± 150 °/s
6000 series: ± 450 °/s
9000 series: ± 450 °/s

Acceleration

± 3 g (3000 series) / ± 4 g (6000 series) / ± 10 g (9000 series)

Heave

± 50 m

Roll / Pitch / Yaw

± 180 ° / ± 90 ° / ± 360 °
(no limits)

Output frequency

0 - 100 Hz
(adjustable output frequencies)

Gyro output

Scale factor error

0.2 % max/min

Angular rate noise

3000 series: 0.050 °/s RMS
6000 series: 0.025 °/s RMS
9000 series: 0.015 °/s RMS

Acceleration output

Acceleration noise

3000 series: 0.0025 m/s2 RMS
6000 series: 0.0020 m/s2 RMS
9000 series: 0.0015 m/s2 RMS

Acceleration accuracy

0.01 m/s2 RMS

Power & interface

Power consumption

6 W

Supply voltage

9 - 36 V DC (24 V nominal)

Internal storage

32 GB

Data protocols

Custom NMEA, ASCII and Binary, Atlas, Gyrocompas 1, Ifremer Victor, MDL, NORSUB 1-8, Simrad EM 3000, SMCA, SMCC, Tokimek PTVG, RDI ADCP, TSS1 and many more.
Read more

Configuration protocols

GET/SET through telnet, serial port and MRU configurator.
Read more

Time synchronization

Sync to host PC, Sync to NTP server, Sync to PPS

Environmental specifications

Temperature range

Operating: -40 to +70 °C
Storage: -40 to +85 °C

Electromagnetic compatibility

IEC 60945/EN 60945
(immunity/emission)

Vibration

IEC 60945/EN 60945

Max shock

2000 m/s2 (half-sine 0.5 msec)
non-operational (10 ms peak)

MTBF (computed)

100 000 h

Easy to use

All Norwegian Subsea Motion Reference Units (MRUs) can be easily configured using the MRU Configurator (free of charge).

Simply define the communication ports and protocols as well as the MRU mounting orientation and location, and you are ready to go.

The MRU Configurator is also a great tool to monitor the outputs in real-time, plot the variables, check the on-board diagnostics and update the MRU firmware.

Read more about the MRU Configurator

Some of the applications where our MRU Subsea are used

Sonar Motion Compensation

Accurate measurements of roll, pitch, and heave are crucial for achieving optimal results when compensating sonar systems for vessel motion, without relying on GNSS or RTK.

Subsea Surveys

Subsea surveys often demand precise tilt measurements (roll and pitch) for various purposes, such as installation tasks or continuous monitoring of tilt changes and deflections in subsea structures.

ROV/AUV

Reliable motion sensors are vital components in the navigation system and motion compensation of payload sensors for ROVs and AUVs.

Floating Wind Base Motion Monitoring

Monitoring the movements and structural integrity of floating wind foundations, including both the base and turbine, along with the anchoring system, is crucial.

Riser Monitoring

The NORSUB Subsea MRU is specifically designed to provide highly accurate measurements of roll, pitch (inclination), and lateral motions in risers.

BOP Monitoring

Accurate motion sensors play a crucial role in the structural monitoring of Blowout Preventers (BOPs), enabling the measurement of inclination and lateral displacements.

All applications