Cygnus FMD System for ROV

Ultrasonic Flooded Member Detector

Designed by our ultrasonic specialists and drawing on all our years of experience and feedback from the subsea industry, this Flooded Member Detector (FMD) combines intelligent, advanced software and electronics with a genuinely simple to use interface. The intelligent design, cutting edge electronics and pioneering, fail-safe design allow the FMD system to be used by operators of varying experience.

The FMD system consists of an ultrasonic transducer and transducer “handler”; the subsea electronics unit; and the reporting software. An ultrasonic flooded member test is conducted from the FMD reporting software – at the surface. Once correct alignment is detected by the contact sensor, the test can be performed and the system gives a simple DRY (Green) / FLOODED (Red) result. The accompanying A-scan is also presented.


The Cygnus FMD has an innovative transducer handling solution which “self-aligns”, ensuring correct contact with the member, even when the ROV approaches from an angle.

The FMD system returns a clear and simple DRY / FLOODED result to the reporting software with results logged back at the surface in the accompanying software – ready to produce as a PDF (or Excel) report for the client.


The Cygnus FMD System is owner-operated and extremely easy to learn and understand.

The need for external contractors is removed due to the system’s simplicity and innovative fail-safe design; the FMD system can be used by a range of operators, with varying experience.


Available in high grade acetal or stainless steel for the subsea environment.

The FMD equipment is designed to the very highest standards and is supported by a three year warranty.


Cygnus is an ultrasonic specialist. 4 decades of industry experience and design expertise combine to make this system the most advanced, effective and reliable Ultrasonic FMD System available.

The purpose-designed algorithm simultaneously uses

– an advanced peak detection algorithm

– low distortion / low noise data acquisition

– advanced signal processing

all of which ensure the highest level of Probability of Detection (PoD) and the elimination of false readings.

The FMD system can only take a measurement when the contact sensor detects transducer contact, ensuring reliable results every time. The reporting software will indicate at the surface if the transducer loses contact during a test.

A System Test Function ensures the reliability of the system before it is deployed.


Displays test results: Indicator shows RED if flooded and GREEN if dry

Displays A-Scans for verification

Logs results for offline analysis

Reports can be generated and exported to PDF and Excel


The same FMD system is both diver or ROV deployable – a unique aspect of the Cygnus FMD that has been purpose designed to make the unit polyvalent for the end user. And the compact design of the transducer is able to get into to hard to reach areas (such as K nodes) where other inspection methods cannot.

A range of options to suit different working depths and varying requirements are available.

And the same system for ROVs can also be used for the diving team.

Transducer0.5 MHz high power piezo composite transducer – single element
Measuring Range200 – 2000 mm member diameter
Resolution1 mm


Diver Communications PSU110-240 AC 50/60 Hz @ 1A (max)
ROV Power Supply12 to 24 volt D.C @ 60mA


DigitalRS232 & RS485
Baud Rate115,200
Date CaptureOn demand 3 shot and varying gain levels
Diver Data LinkRS485 half – duplex
ROV Date LinkRS232 full – duplex suitable for fibre multiplexers


Acetal Electronics Body0.9 kg (95 x 115 mm)
Stainless Steel Electronics Body4 kg (95 x 115 mm)
Acetal Transducer Handler2.5 kg (140 x 170 x 130 mm)
Stainless Steel Transducer Handler4.7 kg (140 x 170 x 130 mm)
120m Umbilical Cable23 kg (340 x 450 x 555 mm)
350m Umbilical Cable87 kg (450 x 600 x 930 mm)
50m Deck Cable13 kg (290 x 380 x 490 mm)
Depth Rating300 msw
Operation Temperature0°C to +75°C
Storage Temperature-40°C to 55°C
Cable Protector
– Provides extra cable protection and an attachment point for divers
Self Aligning Transducer Handler
– Tough Stainless Steel or
– Lightweight Acetal
Handle Options
– T-Bar
– Fishtail
Umbilical Cable
– 120m length
– 350m length
System Test Tank
– Used to run a full system test of the FMD system

1 review for Cygnus FMD System for ROV

Louis P.

Nov 25, 2020 1:36 PM

The new Cygnus Ultrasonic FMD System was perfect for our recent application. Our technicians found the software to be very easy to use with features that ensured a quick and reliable result. It’s a great addition to the Westerton Access capability, offering FMD inspection from the Falcon ROV.

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