Cygnus 4+ General Purpose

Ultrasonic Thickness Gauge

A versatile thickness gauge used for a wide range of applications, the Cygnus 4+ offers: live A-scan display; sequential data logging; a high temperature probe for measuring remaining wall thickness in high-temperatures; and 3 measuring modes.

The Cygnus 4+ General Purpose thickness gauge is a light, tough multi-mode thickness gauge. It features a sunlight readable display with Live A-scan, intuitive menu and sequential data logging for easy reporting and analysis. Used with Cygnus High Temperature Probe, the Cygnus 4+ can measure remaining wall thickness of high-temperature, in-service assets without shutdown or isolation. The C4+ UTG is ideal for plant maintenance, civil engineering, ship inspections, oil and gas facilities as well as high-temperature, in-service thickness surveys across refining, oil and gas, energy and process sectors.

Key Features:

  • Multiple-Echo mode for accurate, through-coat measurements as specified by Classification Societies
  • Echo-Echo and Single-Echo modes for heavily corroded metals with a thin or no coating
  • Deep Coat function ignores coatings up to 20mm thick
  • Manual and automatic gain control
  • Min/max measurement limit functions with visual and vibrate alert
  • Large front sunlight readable LCD display with Live A-scan
  • Water and dust tight IP67 housing
  • Shock and impact proof to US MIL STD 810G
  • Safe operation in explosive atmospheres: Class 1, Division 2, Group D locations only, as defined in NFPA 70, Article 500
  • One and two point calibration
  • Can be upgraded to 6+ at an additional cost.
Measuring ModesMultiple-Echo using 3 echoes to ignore coatings up to 20 mm (0.8 inch) thick
Echo-Echo using 2 echoes to ignore coatings up to 1 mm (0.04 inch) thick
Single-Echo using 1 echo
MaterialsVelocities from 1,000 – 9,000 m/s (0.0390 – 0.3543 in/us)
Accuracy±0.05 mm (±0.002 inch) – in Multiple-Echo measurement mode, when calibrated and measuring the same material as calibrated on
±0.1 mm (±0.004 inch) or 0.1% of thickness measurement whichever is the greatest – in Single-Echo & Echo-Echo measurement modes, when calibrated and measuring the same material as calibrated on
ResolutionMultiple-Echo mode – 0.1 mm (0.005 inch) or 0.05 mm (0.002 inch)
Single-Echo and Echo-Echo modes – 0.1 mm (0.005 inch) or 0.01 mm (0.001 inch)
Probe OptionsSingle crystal probes, Twin crystal probes and High temperature probe
Measurement Range in Steel0.8 – 250 mm (0.031 – 10 inch) depending on selected probe and configuration, material and temperature
Connector2 x Lemo 00
Power3 x AA / R6 batteries
Battery LifeApprox. 10 hours continuous measurement
ElectronicsDual channel pulser
Display2.4 inch QVGA LCD: 47 x 37 mm
Size84 x 130 x 35 mm (3.3 x 5.1 x 1.4 inch)
Weight300 g (10.5 oz) (inc. batteries)
Operating Temp.-10°C to 50°C (14°F to 122°F)
Data Logging5,000 measurements and A-scans per record. Max number records: 100 (soft limit)
Computer SoftwareCygLink allows remote logging and viewing of A-scan graphs
Survey and report generation to PDF file
Graphic analysis of data and statistical calculations
Environmental RatingIP67
Safe operation in Explosive Atmospheres: Class I, Division 2, Group D Locations only, as defined in the National Fire Protection Association Code (NFPA 70), Article 500. Tested using MIL-STD-810G, Method 511.5, Procedure I
MIL STD 810G Method 501.6 (high temp +55°C (131°F))
MIL STD 810G Method 502.6 (low temp -20°C (-4°F))
MIL STD 810G Method 507.6 (humidity 95%)
MIL STD 810G Method 512.6 (immersion 1 metre for 30 mins)
Shock and ImpactMIL STD 810G Method 514.7 (vibration)
MIL STD 810G Method 516.7 (shock 20g)
MIL STD 810G Method 516.7 (transit drop 1.22 m)
StandardsDesigned for EN 15317
ComplianceCE, UKCA, RoHS
Warranty3 years on gauge and 6 months on probe

The Cygnus 4+ General Purpose High Temperature Kit comes with Probe T5B-MAUH 5MHz Twin Element & Twin Lemo 00 to Microdot Lead (050-4502/5)

Weight5 kg

Cygnus 4+ General Purpose Standard Kit WITHOUT PROBE (050-4500/5), Cygnus 4+ General Purpose High Temperature Kit (050-4502/5)

To compliment our ultrasonic thickness gauges we offer a range of ultrasonic probes. The performance of any ultrasonic thickness gauge relies heavily on the probe and its suitability to the material being measured. Therefore, selecting the right probe is vital. All Cygnus’ probes are made from stainless steel and have a hard wear face or a wear membrane to protect the probe.

Variety of Cygnus INOX Probes

  • Stainless steel SINGLE CRYSTAL probes, used in multiple-echo mode, include replaceable membranes for long life, require no zeroing and have a high linear accuracy.
  • Stainless steel TWIN CRYSTAL probes, used in echo-echo and single-echo modes, have improved measurability on extreme back wall corrosion and pitting.
  • Probes for use with the Cygnus 2+, 4, 4+ and 6+ gauges are fitted with a BNC or Lemo 00 connector.

Single Crystal Probes

Twin Crystal Probes

High Temperature Probe

Twin element ultrasonic probe designed for high-temperature, in-service thickness measurements and corrosion surveys across oil & gas, refining, energy and process sectors.

  • No cooling period required – reducing inspection time and facilitating effective measurement
  • For use on hot surfaces up to 300°C
  • Measures remaining wall thickness from 1.5 to 250 mm (0.05 to 9.8 inch) – depending on temperature and material.

6 reviews for Cygnus 4+ General Purpose

Dimitrios Y.

Dec 02, 2015 9:25 AM

We tested the New Cygnus UTM Instruments 2+ and 4+ using single & twin crystals probes.

Tests carried out in our premises and in real working conditions on a 15 years old cargo ship of 10.000 M.Tns.

In our premises we used the following samples, which have been obtained from ships; cropped plates and we use them in our premises for practice purposes.

1.New Coated Steel Plate 10.0 mm.
2.Extremely corroded on both sides Steel Plate, with thickness variation from 4.6 mm to 9.7 mm. Taken gaugings were verified with Outside Callipers.
3.Gray Cast 12.0 mm.
4.Aluminium 6.0 mm.

On the Cargo Ship we focused our tests on the non-coated Inner Bottom Plating of 16.0 mm original thickness.
We got about 100 gaugings which varied between 15.8 mm to 14.4 mm.

All readings, in both tests, were obtained instantly and it should be mention that the new measuring experience with MSI System gave to us a real confidence that the reading we see is the real remaining thickness on that spot.

Apart the user-friendly, high analysis coloured LCD screen and the very easy menu we consider quite important to mention that once we took the instrument in our hands we got an immediate impression of the unit being very rugged. Its tight case together with the strong cable and its twin lemo locking connector allow the operator to focus only to the gauging without worrying at all about the machine.

Jim P.

May 24, 2017 9:26 AM

We approached Cygnus in late 2016 as a result of discovering areas of corrosion in our vessel Lord Nelson in an area specific to the design allowing for disabled access – the watertraps. These areas act to prevent the ingress of water into the vessel given that we can’t have door sills due to the flat sill required for wheelchairs.

Given the age of Lord Nelson, now over 30 years old, it was agreed that to have our own NDT test instrument, while not negating the need for formal Lloyds’ testing, would allow us to keep a check on corrosion and give us a level of confidence as and when areas were discovered. Cygnus kindly offered advice and supplied a Cygnus 4+ Ultrasonic Multi-Mode Thickness Gauge kit including both single and dual crystal probes.

Despite our own relative inexperience in such testing, the results we obtained were confirmed by professional spot testing and proved easy to achieve, the device being simple to calibrate and use, with both probe types.

J D Howard

Jun 20, 2017 9:26 AM

I have used the gauges extensively, often in awkward places where the gauges often take a beating, as well as occasionally getting wet; but the Cygnus gauges have proven to be robust and reliable.

The 4+ meter is very light and easy to carry and has the option to use single crystal or twin crystal transducers, which allows me the ability to measure through thick coatings in deep coat mode, as well heavily corroded metals. When taking measurements with this meter I have found it to be accurate with repeatable results.

The 4+ gauges we use at JDH allow us to see a clear, simple A-Scan as measurements are taken – which in turn allows us to verify measurements. I can also log my measurement [together with the A-scans] and easily transfer them into reports for clients, which is very beneficial.

I am pleased to say that I have always received excellent service from Cygnus Instruments and I will continue to use their products, as I know I have a reliable, robust tool that I can genuinely trust.

Blagoja S.

Oct 01, 2019 9:27 AM

We have purchase 4 pcs. of Cygnus 4+ UTG Kit and 1 pcs. of Cygnus 6+ UTG Kit.
With these instruments we have check more that 3.000.000 points on coated steel pipe. Results were among expected. We are more than satisfied with equipment.

Dale B.

Apr 23, 2020 9:27 AM

Having owned and operated the Cygnus models two and three I recently upgraded to the Cygnus 4+. Cygnus has always been a brand to associate with reliable and accurate UTM readings, and working for a number of high-profile clients and MCA classification societies this accuracy is mandatory. The Cygnus 4+ is not only small and light weight, it is also wrist mounted to keep your hands free. The added functions are endless, and you can add comments in for single readings and also add additional readings (outside of the pre-determined grid) in as you are conducting the survey. This is very useful if defect areas are identified as they can be clearly documented on the spot, rather than having to return after the record is completed. The back-office software is user friendly and has plenty of fields for extra information that can be added apparent to the vessel. After having a demonstration of the Cygnus 4+ at the 2019 Seawork show I ordered the unit the following day. The staff are very helpful and knowledgeable, and the unit arrived promptly. The Cygnus 4+ has helped me become more time efficient and produces a very informative report that is well accepted within the industry.

Mr Monsores

May 06, 2020 9:28 AM

I have already used CYGNUS equipment, they are practical equipment and with excellent response in thickness measurements. Very good brand.

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Cygnus 4+ General Purpose Brochure

Cygnus Surface Gauge Family Brochure

Cygnus Surface Range Comparison Guide

Cygnus 4+ General Purpose – Consumables Reorder Form

Cygnus Videos

Multiple-Echo Ignores Coatings up to 20mm Thick
Measuring Heavily Corroded Metals
Echo-Echo Mode Ignores 1mm Thick Paint
Impact Test
Water Resistance (Dunk Test)
Water Resistance (Hose Test)
Large Bright Display
Large Display and Simple Menu Operation
Measuring Uncoated Small Diameter Pipes
Measuring Small Diameter Pipes Through Coatings
A-Scan on Corrosion
Simple Menu Operation
Auto-Log Measurements
Adding Data Logging Comments
Setting Limit Alerts