MRU Ex
The MRU Ex is a compact and cost-effective solution for hazardous areas including all Ex certificates
MRU Ex
The MRU Ex is a compact and cost-effective solution for hazardous areas including all Ex certificates
Roll and pitch dynamic accuracy of 0.05° Heave accuracy: 5 cm / 5 %
The 6000 series provides high performance 0.02° roll and pitch accuracy
The 9000 series achieves exceptional precision with 0.01° roll and pitch accuracy
The MRU Ex is a cost-effective solution for hazardous areas. Easy to install with pigtail cable and including all certificates and documentation.
• Ex certificate II 2 G Ex d lIC Gb
• Compact and cost effective unit
• Stainless steel unit
• Ethernet & serial line
• Including pigtail cable in custom lengths
The MRU Ex comes in three different versions: 3000, 6000 and 9000 models to accommodate for different accuracy requirements and budgets.
The MRU Ex is also available in an inclinometer version of the MRU that does not include Heave/Surge/Sway outputs.
High accuracy roll, pitch and heave, even in irregular sea states
Ex certificate II 2 G Ex d lIC Gb
Low weight and small footprint enable installation almost anywhere
II 2 G Ex d IIC Gb
Stainless steel AISI 316L
190 x 190 x 205 mm
20 kg (excluding cable)
Pigtail cable - 10 wires used
10 m / 25 m / custom lengths
Ethernet & RS-232 / Ethernet & RS-485 / Ethernet & PPS
TCP, UDP, Modbus TCP, ethernet/IP
Serial, Modbus RTU
0-100 Hz
3000 series: 0.05°
6000 series: 0.02°
9000 series: 0.01°
RMS (dynamic & static)
5.0 cm or 5.0 %
Whichever is greater for 0 to 25 s periods, valid for irregular motions in real sea conditions
± 0.5 °
Magnetic heading
3000 series: ± 150 °/s
6000 series: ± 450 °/s
9000 series: ± 450 °/s
± 3 g (3000 series) / ± 4 g (6000 series) / ± 10 g (9000 series)
± 50 m
± 180 ° / ± 90 ° / ± 360 °
(no limits)
0 - 100 Hz
(adjustable output frequencies)
0.2 % max/min
3000 series: 0.050 °/s RMS
6000 series: 0.025 °/s RMS
9000 series: 0.015 °/s RMS
3000 series: 0.0025 m/s2 RMS
6000 series: 0.0020 m/s2 RMS
9000 series: 0.0015 m/s2 RMS
0.01 m/s2 RMS
6 W
9 - 36 V DC (24 V nominal)
32 GB
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
GET/SET through telnet, serial port and MRU configurator.
Read more
Sync to host PC, Sync to NTP server, Sync to PPS
PPS time synchronization
Heading and velocity aiding
(on request)
Operating: -20 to +60 °C
Storage: -40 to +85 °C
IEC 60945/EN 60945
(immunity/emission)
IEC 60945/EN 60945
2000 m/s2 (half-sine 0.5 msec)
non-operational (10 ms peak)
100 000 h
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.
Accurate measurement of roll, pitch, and heave motions is crucial for assessing the safety of helidecks during helicopter landing and take-off operations.
Accurate measurement of vertical motion at the crane tip or winch is crucial for the operation of Active Heave Compensated (AHC) cranes and winches.
Precise motion measurements are essential for vessel digitalisation, supporting fuel optimisation, route planning, cargo safety and structural health.
Over 1200 Norwegian Subsea Motion Reference Units are in operation world-wide on over 600 vessels, floating and subsea structures.
Some selected customer references.
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From bathymetric surveys to subsea inspections and wave radar systems, our Motion Reference Units (MRUs) have been put to work in a wide range of challenging environments during 2025. As the year draws to a close we take a quick look back at some of the highlights, applications, and collaborations that helped shape another strong year of progress for Norwegian Subsea.
Helideck Motion Monitoring & Weather Data Systems (HMS) provide real-time motion and environmental data essential for flight planning and for pilots to remain in safe control during take off and landing from moving helidecks. The HMS depends on Motion Reference Units (MRU) installed directly on to the support structure that continuously measure the helideck’s movement. Leading HMS manufacturer ShoreConnection chooses MRUs built by Norwegian Subsea.
More than a month has passed since Oceanology International 2026, giving us time to reflect on the value of this major ocean technology and marine science event. For Norwegian Subsea, the London exhibition was defined by a wide range of conversations with both familiar and new faces, many of which are now developing into ongoing discussions across key marine and subsea applications.