Immersed System Behaviour


3-way Accelerometer – Pressure

Measurement Characteristics

  • Depth channel: Piezoresistive pressure sensor with Hastelloy membrane.
  • Range: 0 to 6000m.
  • Accuracy: < ± 0.5%, i.e. ± 30m.
  • Maximum resolution: 3m.
  • Overload rating: 6600 dBars.
  • 3 channels for measurement of Acceleration:
  • 3 piezoresistive accelerometers with various ranges can be used: ±2g, ±20g or ±100g
  • Accuracy: 1%
  • Mechanical aspect:
  • Limited to 400G for the ±2g and ±20g sensors
  • Limited to 2000G for the ±100g sensor



Data Logger

Energy: Lithium batteries (factory replacement recommended).
Autonomy: > 50 days at a sampling rate of 10s, 5 days at a sampling rate lower or equal to 1s.
Sampling frequency: 200Hz maximum, which corresponds to a sampling rate of 5ms max.
1Mb memory capacity (4Mb optional).

Mechanical Characteristics

Body in titanium and plastic.
Dimensions: diameter 40mm, length 235mm.


S3AP allows to measure of accelerations along the axes of its housing or along 3 orthogonal axes, in various ranges (±2g, ±20g and/or ±100g).

It also measures the depth of immersion, down to 6000 metres.

It is used to monitor the behaviour of immersed systems (shocks sustained by the systems when they are deployed), but also to measure the penetration of corers in sediment.

SF strain gauge

 Force data logger (2, 5,10 or 35 tons)


Sensor of the type Traction in S

  • Measuring cell: temperature compensated measurement bridge
  • Overload:
    1.5 times the nominal load without recalibration
    2 times the nominal load with recalibration
    4 times the nominal load at failure
  • Material: entirely stainless steel
  • Max. operating depth: 300m
  • 2-ton range – Accuracy: 10kg, resolution: 0.9kg
  • 5-ton range – Accuracy: 25kg, resolution: 2.2kg
  • Approx. weight in air: 4kg
  • Approx. weight in water: 3kg
  • Dimensions (mm): 214 x 85 x 60
  • 10-ton range – Accuracy: 50kg, resolution: 4.5kg
  • Approx. weight in air: 5Kg
  • Approx. weight in water: 4Kg
  • Dimensions (mm): 249 x 85 x 60
  • 1Mb Flash-type memory with data compression (possible extension)
  • Sampling: from 0.01s to 99hrs
  • Power: overmoulded lithium batteries, average battery life : 3 years (depending on usage)
  • Programmable starting: manual, by threshold detection, timed… (15 On/Off modes available)
  • Mode of storage of measurements: NORMAL, MINIMUM, MAXIMUM, AVERAGE





Download data sheet



Measurement of tractive stress of towing gillnets, on buoy anchoring or on any structure held in place by cables (aquacultural cages…).

For depths down to 50 meters, reading can be performed under water using a waterproof Data Pencil, in which case the SF data logger can remain in station.

Available in a ±2.5 ton tractive and compressive stress data logger version.



300m or 6000m Pressure & Tilt data logger


  • Tilt range: ± 85°
  • Resolution: < 0.1° at 30°
  • Accuracy: ±0.3° at +20° and -20°
  • Tilt sensor: Accelerometer ±2g
  • Pressure sensor: Piezoresistive (case and diaphragm made of Hastelloy)
  • Response time of sensors: 10 ms
  • 300m Depth range (S2IP300) Accuracy: 0.9m, Resolution : < 0.15m
  • 6000m Depth range (S2IP6000) Accuracy: 18m, Resolution : < 3m
  • Weight (in air): 600g
  • Length: 235 mm
  • Diameter: 40 mm
  • Material: Titanium and Ketron
  • Sampling rate: Programmable from 0.05 s to 99 hrs
  • Programmable starting: immediate, delayed, timed or set threshold (depth or tilt)
  • Memory capacity (*): 1Mb (with data compression) (*) the recording autonomy depends on the resolution and the sampling rate.


S2IP measures and records the pressure and the tilt of immersed instruments such as the particle collectors or trawl panels.

The measurements of tilt are made along 2 perpendicular axes.

S2IP can have an autonomy in excess of one year depending on the settings and the sampling rate



4 AXIS Motion Reference Unit

Also available for Inertial Navigation (MRU-500)

This is more than just an Attitude sensor and Accelerometer. The MRU-100 is designed to accurately measure pitch, roll, heading and heave in surface and underwater applications under static and dynamic conditions using gyro compensation.

The MRU-100 can be mounted on marine vessels, ROVs (remotely operated vehicles), and AUVs (autonomous underwater vehicles) to help support your mission objectives such as sonar surveys, imaging sonar compensation, attitude measurement and orientation.

The MRU-100 motion reference unit is the new leader in its class to give you:

  • Gyro compensated pitch, roll, heading and heave output for operations in static and dynamic conditions
  • Output string modified to your specification
  • Installation in any orientation
  • Magnetic interference detection
  • Optional pressure / temperature sensors
  • High Accuracy version Meets IHO Standard SP1 Data output


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