Cygnus Instruments Ltd


Cygnus Instruments Ltd is the leading manufacturer of multiple-echo ultrasonic thickness gauges used for measuring remaining metal thickness without the need to remove protective coatings.

Following extensive customer engagement, Cygnus have developed a new range of ultrasonic thickness gauges which still use the well established multiple-echo technique but incorporated within the PLUS models is single-echo and echo-echo measuring modes using twin crystal probes.  Single-echo and echo-echo can assist in obtaining measurements in areas of extreme corrosion or back wall pitting.

Non Destructive Testing

Cygnus Instruments provide a range of measuring equipment that is used in non-destructive testing environments which calls for the measuring of materials and structures without damaging or removing the components.

Underwater Thickness Measurements

The range of Cygnus underwater thickness gauges includes: the diver wrist-mountable data logging gauge with a large bright AMOLED A-scan display; ROV mountable range depth rated up to 4,000 meters with optional probe handling solutions; and the original RINA approved divers hand-held gauge depth rated to 300 meters.

Surface Thickness Gauging

Cygnus' range of surface thickness gauges includes: an ATEX approved intrinsically safe gauge for use in Zone 0, Zone 1 hazardous areas and requires no plant shutdown or hot work permit; hands free gauge designed for climbing or rope access work where safe hands free operation is paramount; general purpose gauge with A-scan display and sequential data logging; and a more advanced gauge with A-scan and B-scan display, comprehensive data logging, manual gain control, Bluetooth, and much more.

Multiple-Echo Measuring Mode

All Cygnus surface and underwater thickness gauges use the Cygnus pioneered Multiple-Echo technology which provides accurate, reliable and error-checked thickness measurements while ignoring coatings up to approx. 6 mm thick (or 20 mm thick when used in Deep Coat mode).  It is generally recommended by some of the major classification societies to use the Multiple-Echo technique when performing ship surveys / inspections.

Echo-Echo Measuring Mode

Incorporated within all Cygnus PLUS thickness gauges and the Cygnus DIVE underwater thickness gauge, the Echo-Echo technique can read through coatings up to 0.5 mm thick.  The focussed V-Path which is created by the ultrasound from a twin crystal probe travelling at a slight angle helps to ensure a strong enough signal gets back the receiving side of the probe when used on pained metals with heavy back wall corrosion or pitting.


Single-Echo Measuring Mode

The Cygnus DIVE underwater thickness gauge and the Cygnus PLUS ultrasonic thickness gauges all incorporate the Single-Echo technique which is beneficial when there's particularly heavy front and/or back wall corrosion.  Ultrasound reverberates inside material being tested therefore, using just one focussed beam helps to keep this to a minimum.  This measuring mode is particularly helpful when used on irregular geometric shapes, highly attenuative materials, plastic pipes and applications with extremely heavy back wall pitting or corrosion.

ATEX Certified Intrinsically Safe Thickness Gauge

Designed for safely measuring metal thickness to determine wastage or corrosion in potentially explosive environments, the Cygnus 1 Intrinsically Safe thickness gauge is a rugged, shock-proof Multiple-Echo ultrasonic surface thickness gauge. By using multiple echo technology the metal thickness gauge measurements are error checked using 3 return echoes to provide repeatable, reliable results.  Having been ATEX / CSA approved intrinsically safe, this gauge can be used in Zone 0, Zone 1 hazardous areas and requires no plant shutdown or hot work permit.

Hands Free / Rope Access Work Thickness Gauge

The Cygnus 2 and 2+ Hands Free ultrasonic thickness gauges have an end-mounted, rotatable, OLED display which makes them ideal for climbing and rope access applications where safety requires hands-free gauging.  While the Cygnus 2 gauge only uses the Multiple-Echo technique, the Cygnus 2PLUS uses Multiple-Echo, Echo-Echo and Single-Echo measuring modes providing the user with the flexibility at alternate between the three modes without having to change gauges.

General Purpose Ultrasonic Thickness Gauge

There are two general purpose thickness gauges, the Cygnus 4 which uses just the Multiple-Echo technique for measuring remaining metal thickness and the Cygnus 4PLUS which uses the Multiple-Echo technique as well as Single-Echo and Echo-Echo measuring modes.  The Cygnus 4PLUS also has an A-scan display and sequential data logging.  Both thickness gauges have been designed for harsh environments and have a colour LCD display which can be viewed in all lighting conditions.

A-Scan, B-Scan and Data Logging Thickness Gauge

With its unique dual display, the Cygnus 6+ PRO is the most advanced surface thickness gauge in the Cygnus range.  Offering features such as A-scan and B-scan display, comprehensive data logging, manual gain control, Bluetooth, and much more.  This gauge also uses three versatile measuring modes: Multiple-Echo to provide extremely accurate measurements while ignoring protective coatings up to 20 mm thick; Echo-Echo for measurements on painted metals but with heavy back wall corrosion / pitting and; Single-Echo for measurements on uncoated surfaces with heavy front face and/or backwall corrosion and attenuative materials such as cast metals or plastics / composites.

Extremely Rugged Ultrasonic Thickness Gauges

Able to withstand the harshest operating conditions and an enclosure that has met the tough American Military Standard MIL SPEC 810G, the new MK5 surface thickness gauges are extremely rugged.  These new gauges can survive drops, vibration, dust and water ingress (IP67) together with low and high temperature cycling.

Heavy Duty Ultrasonic Thickness Gauge

The Cygnus Heavy Duty ultrasonic thickness gauge is dirt resistant, dust resistant and water resistant and has been designed for use in tough and demanding environments where a rugged construction is essential to accurately gauge corrosion measurement and determine metal thickness without having to remove protective coatings.  Its shock-proof construction is able to withstand accidental drops, bangs and knocks.

Divers Wrist-Mountable Underwater Thickness Gauge

The latest underwater thickness gauge from Cygnus Instruments which is designed to be wrist-mounted on the divers forearm and has a super-bright AMOLED display providing visible thickness readings in poor underwater conditions.  The Cygnus DIVE has a selectable A-scan display and data logging feature which can store up to 5000 measurements and A-scans.  Using Multiple-Echo, Echo-Echo and Single-Echo measuring modes, this gauge provides the diver with the ability to alternate between these measuring modes without having to swap gauges through an inspection.

Divers Helmet View Display

The Cygnus DIVE underwater thickness gauge can be supplied with an optional HelmetView™ which is a remote display that is mounted to the divers helmet allowing the diver to view readings in blackwater conditions where visibility is poor.  This remote display shows the readings or echo bars which would be shown on the Cygnus DIVE gauge will also indicate when a reading is being logged by the gauge.

Data Logging

There are three ultrasonic thickness gauges in the Cygnus range which offer data logging, these include: the Cygnus 4+ General Purpose with sequential data logging; the Cygnus 6+ PRO offering a more comprehensive data logging feature; and the Cygnus DIVE underwater thickness gauge which stores up to 5,000 measurements and A-scans, each stable measurement is automatically logged without the diver having to press any buttons.

A-Scan Display

An A-scan display helps the user to verify the true back wall reading in difficult measuring applications.  There are three thickness gauges in the Cygnus range which offers this feature, the Cygnus 4+ General Purpose and Cygnus 6+ PRO surface ultrasonic thickness gauges and the underwater ultrasonic thickness gauge - Cygnus DIVE.

B-Scan Display

Currently there is only one gauge within the Cygnus range that offers live B-scan display, this is the Cygnus 6+ PRO multi-mode surface thickness gauge.

Stable Measurement Indicator

Cygnus Instruments has developed MSI™ (Measurement Stability Indicator) which is used to help indicate a stable reading when a Cygnus thickness gauge is used in Single-Echo and Echo-Echo measuring modes.  This technique is currently available on all the Cygnus PLUS surface thickness gauges and the Cygnus DIVE underwater thickness gauge.

Hand-Held Diver Underwater Thickness Gauge

The Cygnus Underwater gauge is the original underwater thickness gauge developed by Cygnus Instruments.  This diver hand-held subsea thickness gauge uses the Multiple-Echo technique, is depth rated to 300 metres and provides accurate metal thickness measurement through coatings up to 20 mm thick.

Small Observation ROV Mountable Thickness Gauge

Built in conjunction with VideoRay and pressure tested to 500 m, the Cygnus Mini ROV mountable thickness gauge has been designed to be mounted onto small observation ROVs allowing the operator to carry out subsea surveys in areas that had previously been infeasible using divers or larger ROVs.

Subsea Thickness Gauges for Work Class ROVs

Designed to be mounted onto work class Remotely Operated Vehicles (ROVs), these multiple-echo subsea thickness gauges are available in two depth ratings - 2,000 and 4,000 meters.  They are truly versatile and designed to measure metal thickness through coatings in the harshest operating conditions.

ROV Probe Handling Solutions

Cygnus Instruments offers three ROV probe handling solutions which enables the ROV pilot to easily navigate the ultrasonic probe to the material being tested when performing subsea inspections, these include the:

  • Cygnus G1 - designed for use on observation, inspection and light-work class ROVs
  • Cygnus S1 - designed for use on inspection and medium sized ROVs carrying out ship hull inspections
  • Cygnus W1 - designed for use on work class ROVs. 

Ultrasonic Hatch Cover Leak Detector

Cygnus Instruments also manufacture an ultrasonic hatch cover leak detector, Cygnus Hatch Sure, which allows the surveyor / inspector to quickly and effectively evaluate cargo hold hatch covers and door seals to determine water leaks and weather tightness.

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