Ultrasonic Thickness Gauge, Dedicated Underwater, Model ROV by Cygnus

Two underwater mountable multiple echo ultrasonic thickness gauges. Pressure tested to depths of 1000 m and 3000 m for use with ROV.

Cygnus Instruments offers two dedicated ROV mountable thickness gauges. The units have been designed to be mounted onto most types of work class ROV with a manipulator facility. The shallow water version (Cygnus ROV 1000) is pressure tested to 1000 m. The deep water version is pressure tested to 3000 m (Cygnus ROV 3000). Dedicated software displays the time, date and thickness readings on the surface. All readings can be stored.

Kit Contents
  • Instrument.
  • Heavy duty, remote 2.25 MHz, 13 mm diameter probe
    with 5 m of cable.
  • Sealed 4-way connector with fly lead.
  • RS-422 to RS-232 converter.
  • Test cable.
  • Remote display and datalogging software
    (Windows compatible).
  • Spare membranes and "O" rings.
  • Steel test block.
  • Operating manual.
  • Carrying case.
  • Not included: PC or laptop computer with available serial port or USB port.



  • Shallow water version pressure tested to 1000 m (3,300 ft).
  • Deep water version pressure tested to 3000 m (10,000 ft).
  • 16 ft (5 m) of probe cable for routing around most ROV's.
  • Power taken from ROV.
  • Only one twisted pair required to transfer data to surface.
  • Probe does not need to touch surface under test -- measurements can be taken through 5 mm of water.
  • Readings not influenced by the probe orientation.
  • Dedicated software for displaying measured results, storing measurements and calibrating gauge.

Cygnus Multiple Echo Technology

With multiple echo technology, readings are taken by measuring the time delay between any three consecutive backwall echoes. The time T1 (for coating thickness) is ignored. The times T2 and T3 are equal to the time that it takes for sound to travel through the metal. Only by looking at three echoes can the measurements be made for the metal thickness, where T2 = T3.


Pressure test

1000 m (Cygnus ROV 1000)
3000 m (Cygnus ROC 3000)


Sound velocities between 1000 m/s and 9995 m/s.


3 mm to 250 mm with 2.25 MHz probe.
2 mm to 150 mm with 3.5 MHz probe.
1 mm to 50 mm with 5 MHz probe.


±0.1 mm or ±0.05 mm


0.1 mm or 0.05 mm


Remote single-crystal, soft-faced compression.
13 mm - 2.25 MHz, 3.5 MHz or 5 MHz
19 mm - 2.25 MHz


7.5 - 30 Vdc @ 150 mA (max)


237 x 70 mm

Weight in air

550 g (1.2 lb)

Operating Temperature

-10ºC to +50ºC


Standard RS-422


3 years

Surface Requirement

PC or laptop with VGA screen and available COM port.