Measures metal thickness to determine wastage or corrosion
accurately, quickly and without removing protective coatings


  • RINA approved (Certificate No. 2009DGPO787)
  • Auto – Probe Recognition (APR)
  • “Deep-Coat” mode for measuring through coatings up to 20 mm
    (3/4″) thick
  • Easy calibration using convenient buttons
  • Rugged, durable, shock-proof construction
  • Stable calibration – linear accuracy – no zero adjustment
  • Large bright LED display for poor visibility
  • Pressure rated to 300 m (1,000 ft) depth
  • Heavy-duty sealed unit with double ‘O’ ring protection
  • Self verification of measurements to ensure accuracy
  • Echo strength indicator to aid measurement
  • All probes are protected by a membrane to prevent damage
  • Various probe options
  • Two rechargeable battery packs with charger
  • Fixed head probe option for single-handed use.

Benefits of Cygnus Multiple Echo

  • Measures remaining metal thickness on corroded and coated
  • All measurements are error checked using 3 return echoes to give
    repeatable, reliable results
  • Accepted by all major classification societies
  • Greatly reduces inspection time and costs
  • Echo strength indicator to aid measurement.

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

Gauge Kit Contents

The instrument, heavy-duty remote 2.25 MHz 13 mm (1/2″) diameter probe, nose cone tommy bar, probe locking ring key, 2 rechargeable batteries, and battery charger, spare membranes and ‘O’ rings, steel test block, lanyard, operation manual, pressure test and calibration certificates, Molykote grease and carry case.

  1. Cygnus UW Gauge Body.
  2. Lanyard & Molykote.
  3. Two Rechargeable NiMH Battery Packs.
  4. Battery Charger and Leads.
  5. Nosecone, Cable & Remote Probe (1.5 m).
  6. Membrane Couplant.
  7. Accessories: Spare O-Rings, Spare Membranes, Membrane. Locking Ring Key, 15 mm (½”) Test block, Tommy Bar.

The Operating Manual and Documentation are attached to the lid of the case.


Maintenance and safety checks of metal thickness for:

  • Ships hulls
  • Semi substructures
  • Anchor chains
  • Subsea pipelines
  • Offshore structures, jackets
  • Storage vessels, FPSO’s
  • Dock gates, piers, jetties, and pipings.

…plus many more.



Sound velocities between 2000 m/s and 7000 m/s (0.059 and 0.31 in/microsec) -covers virtually all common engineering materials

Range in Steel

3 mm – 250 mm (0.110″ – 9.995″) with 2.25 MHz probe
2 mm – 150 mm (0.065″ – 6.000″) with 3.5 MHz probe
1 mm – 50 mm (0.045″ – 4.000″) with 5.0 MHz probe


0.1 mm (0.005″) when calibrated in accordance with Cygnus Instruments
Calibration Procedures


0.1 mm or 0.05 mm (selectable) (0.005″ or 0.002″)


Remote single crystal soft-faced
6 mm (1/4″) – 5 MHz
13 mm (1/2″) – 2.25, 3.5 or 5 MHz
19 mm (3/4″) – 2.25 MHz
(Lower frequency probes offer better
penetration on heavy corrosion/coatings)


NiMH rechargeable battery pack

Battery Life

30 hours’ (continuous measuring)


Large, bright LED display


235 mm x 75 mm (8 3/8″ x 3″)


950 g (2.1 lbs) – with remote probe
860 g (30.3 oz) – with fixed head probe

Operating Temp.

-10°C to +50°C (14°F to 122°F)


IPX8 continuous 300 m (984 ft) rating


CE, British Standard BS EN 15317:2013
(Specification for the characterisation and verification
of ultrasonic thickness measuring equipment)


RoHS, WEEE compliant