Cygnus 1 Ex: Intrinsically Safe UTG for Hazardous Zones
Posted: 2026-4-8
By:
Cygnus Instruments
Source:
Cygnus Instruments
More than three years after the launch of the Cygnus 1 Ex, Cygnus Instruments Ltd continues to see this intrinsically safe ultrasonic thickness gauge (UTG) stand out as one of its most trusted and celebrated solutions for hazardous environments.
Founded in 1983 by George Edes, Cygnus Instruments Ltd pioneered the use of ultrasonic thickness measurement for non-destructive testing (NDT) of ship hulls. From its headquarters in Dorchester, South West England, the company has grown into a global leader in multiple echo ultrasonic thickness gauges used to measure remaining metal thickness across a wide range of industries – including marine, oil and gas, civil engineering, and plant maintenance.
What Makes the Cygnus 1 Ex Unique Among Ultrasonic Thickness Gauges?
The Cygnus 1 Ex is distinguished by its full intrinsic safety certification, enabling it to operate in all hazardous gas environments – including ATEX / IECEx / UKEX Zones 0, 1, and 2 – as well as coal mines and combustible dust zones (21 and 22).
Where many UTGs require shutdowns or hot-work permits, the Cygnus 1 Ex allows safe, frequent in-service thickness measurements in explosive atmospheres. It combines rugged usability with Cygnus’ industry-leading multiple-echo technology, enabling accurate through-coating measurements while ignoring coatings up to 20 mm thick.
When paired with the Cygnus High-Temperature Ex Probe, the device can perform on-stream corrosion inspections on hot assets – without shutdowns or system depressurisation. It is also the only ultrasonic thickness gauge approved for ATEX Zone 0, the highest safety classification.
What Does Live Measurement in Hazardous Zones Mean for Operators?
For operators, the ability to conduct live ultrasonic thickness measurements in hazardous or prohibited zones delivers major operational advantages:
• Improved safety – No need for hot-work permits or additional risk mitigation procedures.
• Reduced downtime – Inspections can be carried out without shutting down plant or equipment.
• Lower inspection costs – No coating removal, depressurisation, or system isolation required.
• Greater efficiency – Enables more frequent inspections as part of preventative maintenance.
• Enhanced asset integrity management – Operators can monitor corrosion trends more reliably.
Because the Cygnus 1 Ex is certified for use anytime and anywhere within hazardous zones, it supports continuous, proactive maintenance strategies that extend asset life and reduce long term operational risk.
How Important Is the Multiple Echo Technique for Through Coating Accuracy?
Cygnus Instruments is the originator of the Multiple Echo technique, now widely recognised and specified by Classification Societies for Ultrasonic Thickness Measurement (UTM) in the marine industry.
Unlike conventional UTGs that rely on the first returned echo, the Cygnus multiple echo method analyses multiple back wall echoes from the metal substrate. This automatically ignores the coating layer, ensuring:
• Accurate readings of remaining metal thickness
• No need to remove protective coatings
• Preservation of corrosion protection systems
• Significant time and cost savings
With the addition of the Deep Coat function, the Cygnus 1 Ex can ignore coatings up to 20 mm, making it ideal for heavily coated or insulated assets.
Founded in 1983 by George Edes, Cygnus Instruments Ltd pioneered the use of ultrasonic thickness measurement for non-destructive testing (NDT) of ship hulls. From its headquarters in Dorchester, South West England, the company has grown into a global leader in multiple echo ultrasonic thickness gauges used to measure remaining metal thickness across a wide range of industries – including marine, oil and gas, civil engineering, and plant maintenance.
What Makes the Cygnus 1 Ex Unique Among Ultrasonic Thickness Gauges?
The Cygnus 1 Ex is distinguished by its full intrinsic safety certification, enabling it to operate in all hazardous gas environments – including ATEX / IECEx / UKEX Zones 0, 1, and 2 – as well as coal mines and combustible dust zones (21 and 22).
Where many UTGs require shutdowns or hot-work permits, the Cygnus 1 Ex allows safe, frequent in-service thickness measurements in explosive atmospheres. It combines rugged usability with Cygnus’ industry-leading multiple-echo technology, enabling accurate through-coating measurements while ignoring coatings up to 20 mm thick.
When paired with the Cygnus High-Temperature Ex Probe, the device can perform on-stream corrosion inspections on hot assets – without shutdowns or system depressurisation. It is also the only ultrasonic thickness gauge approved for ATEX Zone 0, the highest safety classification.
What Does Live Measurement in Hazardous Zones Mean for Operators?
For operators, the ability to conduct live ultrasonic thickness measurements in hazardous or prohibited zones delivers major operational advantages:
• Improved safety – No need for hot-work permits or additional risk mitigation procedures.
• Reduced downtime – Inspections can be carried out without shutting down plant or equipment.
• Lower inspection costs – No coating removal, depressurisation, or system isolation required.
• Greater efficiency – Enables more frequent inspections as part of preventative maintenance.
• Enhanced asset integrity management – Operators can monitor corrosion trends more reliably.
Because the Cygnus 1 Ex is certified for use anytime and anywhere within hazardous zones, it supports continuous, proactive maintenance strategies that extend asset life and reduce long term operational risk.
How Important Is the Multiple Echo Technique for Through Coating Accuracy?
Cygnus Instruments is the originator of the Multiple Echo technique, now widely recognised and specified by Classification Societies for Ultrasonic Thickness Measurement (UTM) in the marine industry.
Unlike conventional UTGs that rely on the first returned echo, the Cygnus multiple echo method analyses multiple back wall echoes from the metal substrate. This automatically ignores the coating layer, ensuring:
• Accurate readings of remaining metal thickness
• No need to remove protective coatings
• Preservation of corrosion protection systems
• Significant time and cost savings
With the addition of the Deep Coat function, the Cygnus 1 Ex can ignore coatings up to 20 mm, making it ideal for heavily coated or insulated assets.
