Specifically designed for underwater remotely operated vehicles, Cygnus offers a dedicated ROV Mountable thickness gauge, depth rated to 2,000 m. This mountable measurement gauge again, benefits from the multiple-echo technology found in all our ultrasonic measuring devices. It is truly versatile and designed to measure metal thickness through coatings in the harshest operating conditions.

Dedicated software reveals the date, time and thickness readings on the surface which may be logged or stored. In addition, a Topside Repeater (TSR) is available providing the ability to present the thickness measurements remotely and overlay them on to a video signal. This permits the measurements to be superimposed on the ROV camera’s monitor screen.

Cygnus Instruments builds all of its equipment in the UK using only genuine and original parts and components – including Lemo® Connectors and Peli® Cases.

Kit contents

  • ROV 2000m MK5 UTG Kit, depth rated to 2,000 meters.
  • Selectable Deep Coat mode for measuring through coatings up to 20 mm thick.
  • Supplied with CygLink software to display and log thickness measurements from the ROV on a computer at the surface which can be saved to a file and printed out.
  • CygLink has two data logging facilities: Quick Log for simple recording of thickness measurements and; Structured mode with four templates available – Single Point, Multi Point, Grid Point and Key Point.
  • The ROV gauge sends thickness measurement data to the surface via an RS-422 serial link, Cygnus can supply the RS-422 umbilical cable up to 1,200 m in length. For longer distances the ROV gauge can output data in RS-232 mode.
  • Fitted with a safety Pressure Relief Valve and Securing Eye.
  • Easy calibration at the surface via CygLink software or Topside Repeater (TSR) unit.
  • Removable end plate for full serviceability with access to the Option Switches, Fuse and Status LED.
  • Wet mateable ‘MC’ style underwater connectors.


MaterialsSound velocities between 1000 m/s to 9995 m/s
Measurement Range in Steel3 mm – 250 mm with 2.25 MHz probe
2 mm – 150 mm with 3.5 MHz probe
1 mm – 50 mm with 5 MHz probe
Accuracy±0.1 mm (±0.004”) or 0.1% of thickness measurement, whichever is greatest, when calibrated in accordance with Cygnus Instruments calibration procedure
Resolution0.05 mm
Size88.90 mm x 205 mm (inc. fittings)
Weight0.975 kg
Operating Temp-10 °C to +50 °C
Testing3 km depth
CommunicationsRS-422 Simplex Single Pair or RS-232 TXD 2400 or 9600 Baud
ComplianceBritish Standard BS EN 15317:2013 (Group 1)
EnvironmentalRoHS, WEEE Compliant

Kit contents

  • ROV power and data cable with flying leads
  • Membrane couplant
  • ‘K3’ RS-422/485 to RS-232 converter
  • RS-232 to USB converter
  • ROV probe cable with heavy duty remote probe (5 m)
  • Cygnus ROV gauge
  • USB flash drive CygLink installation and operating manual in PDF format
  • ROV power and data test cable and connectors
  • Accessories in case: spare O-rings; spare membranes; membrane locking ring key; 15 mm test block; spare 1A fuses; 3mm allen key; silicone grease sachets.

Probe handling solutions

For optimum performance of the ultrasonic thickness gauge it is essential to utilise the appropriate probe for the specific material being tested. Here below are the probe options available.

Single crystal soft-faced compression13 mm – 2.25, 3.5 or 5 MHz



The Cygnus Topside Repeater (TSR) is available as an option and has the facility to display the thickness measurements remotely and overlay them on to a video signal. This allows the measurements to be superimposed on the ROV camera’s monitor screen.

Probe handling solutions

Cygnus G1 Observation, Inspection, Light Work Class ROV Probe Handler

The Cygnus G1 Probe Handler is designed for use on Observation, Inspection and Light-work class ROVs. Constructed from acetal it is both strong and lightweight it features an adjustable mounting bracket allowing optimum positioning of the UT probe. The UT probe is located in an articulated mount that allows up to 15 degrees of movement in both planes allowing automatic alignment of the probe face to the measurement surface making the ROV pilot’s job easier.

Cygnus S1 Probe Handler for ROV Ship Hull Inspection

Complementing the Cygnus range of ROV Mountable thickness gauges, the NEW Cygnus S1 Probe Handler is developed for use on Inspection and Medium sized ROVs carrying out ship hull inspections.

Cygnus W1 Work Class ROV Probe Handler

Complementing the Cygnus ROV Mountable thickness gauges, the Cygnus W1 Work Class ROV Probe Handler has been developed to offer an engineered probe-handling solution for Work Class ROV thickness gauging operations.

Download CYGNUS ROV MOUNTABLE​ brochure

Download Subsea Range​ brochure