Biz Wave Cygnus Instruments Feature

Biz Wave: Cygnus Instruments Ltd

Cygnus DIVE
Photo property of Cygnus Instruments Ltd.

Cygnus Instruments founded the multiple-echo technique, now used worldwide to measure metal thickness. What improvements have you made to this technology since then?

All Cygnus thickness gauges use the multiple-echo technique. Cygnus has developed different gauge housings to be used in different situations such as:

  • Cygnus 1 Intrinsically Safe thickness gauge for use in hazardous environments
  • Cygnus 2 Hands Free thickness gauge for rope access surveys
  • Cygnus ROV Mountable thickness gauges for use on remotely operated vehicles

Our latest underwater thickness gauge for diver use, the Cygnus DIVE, has the addition of single-echo mode using a twin crystal probe to increase the range of applications the thickness gauge can be used on. For example, it can now be used to measure the thickness of anchor chain links. This also has the added benefit of MSITM (Measurement Stability Indicator), exclusive to Cygnus; this indicates when a measurement is stable by changing the reading numerals from red to yellow.

How much training is involved to learn how to use your instruments?

There is only a small amount of training required to use Cygnus thickness gauges as they are designed to be simple to operate. However, it can be advantageous that the operator has ultrasonic inspection training. Often the level of training and qualifications needed depends on the requirements of the organization that the inspection work is being carried out for. For example, in shipping the operator might be required to be a trained marine surveyor.

What types of facilities and environments do you use to test your instruments?

Cygnus subsea thickness gauges are pressure tested in a pressure chamber, at the Cygnus manufacturing facility, and supplied with a relevant pressure test certificate.

All Cygnus thickness gauges are supplied with a calibration certificate which is valid for 12 months.
Cygnus thickness gauges also have IP ratings.

Cygnus Hatch Sure
Photo property of Cygnus Instruments Ltd.

What are the distinguishing characteristics between your surface and subsea thickness gauges?

All Cygnus subsea thickness gauges are waterproof sealed: The Cygnus Underwater and Cygnus DIVE thickness gauges are depth rated to 300 meters; the Cygnus Mini ROV Mountable thickness gauge is depth rated to 500 meters; the two Cygnus ROV Mountable thickness gauges are depth rated to 2,000 meters and the other to 4,000 meters. The Cygnus subsea thickness gauges are supplied with probes that are “potted” and come with integral cables, to ensure they are waterproof.

All of the Cygnus subsea thickness gauges are available with topside repeaters and surface displays.

What’s the basic difference between the Cygnus Hatch Sure industrial leak detectors?

Cygnus manufacture the Cygnus Hatch Sure ultrasonic leak detector for checking that hatch covers on bulk carriers are weather-tight. This uses an ultrasonic transmitter which would be placed in the ships hold, the hatches are closed and then the receiver is used to detect any ultrasound escaping through leaks and gaps in the hatch seals. If ultrasound can leak through these gaps, then water could leak in and damage the cargo. This Cygnus Hatch Sure is an ABS type approved product.

Your products are distributed worldwide – what is one challenge in creating products that adhere to all government standards?

Cygnus thickness gauges are calibrated to CE, British Standard BS EN 15317:2013. This means that the calibration blocks that Cygnus have in their service departments are manufactured to the requirements set out in this standard.

The Cygnus 1 Intrinsically Safe thickness gauge is rated to ATEX {Ex} I M 1 Ex ia I Ma (Ta = 0 to 45 C), {Ex} II 1 G Ex ia IIC T6 Ga (Ta = 0 to 45 C) and there is also a version rated to the US Standard CSA Class 1 Group A, B, C & D Division 1. We are continually audited annually to ensure we maintain these ATEX and CSA certifications.
Cygnus gauges have IP ratings and Cygnus has ISO:9001.

Cygnus 2 Hands Free
Photo property of Cygnus Instruments Ltd.

Cygnus also offers accessory tools to assist with thickness measurement. Have you always offered these, or were these developed due to increased demand?

The surface preparation tools are a recent addition to the Cygnus product range, to offer surveyors the chance to order the equipment they need from one source.

The probe handlers have been in the Cygnus range for several years now and these are designed to be used with the Cygnus ROV Mountable thickness gauges. They assist in holding the probe stable to make it easier to obtain thickness measurements in subsea environments which can involve rough water and strong currents.

Your Cygnus 2 Hands Free is used in rope access. Can you briefly give a real-life scenario to describe the application of this instrument?

An engineer is required to perform a bridge survey to measure the metal thickness, but the only way to access the metal supports is by rope access.

The Cygnus 2 Hands Free has an end-mounted display and only four buttons to operate. This means it can be mounted onto the surveyor’s belt or alternatively worn around their neck with the neck strap. They can then concentrate on maneuvering around using the ropes and only need to place the probe on the surface being measured, using one hand to obtain readings. As the Cygnus 2 Hands Free is so easy to use, this means the engineer can concentrate on the job and not on how to operate the thickness gauge. This is Cygnus’ most popular product.


Since 1983, Cygnus Instruments Ltd has produced products and technology for measuring metal thickness across the industry. Their facilities are in the UK, but they have distributors worldwide.