Rolling Ultrasound Scanners

COBRI 3.0 – The NDT Ultra Roller

Elop AS has developed an unique rolling scanner for fast data acquisition on concrete. The handheld scanner has completely dry coupling and shows live 3D video of the structure during inspection. The ultrasound scanner system can detect cracks, voids, air pockets, delaminations, rebars & technical pipes inside concrete structures. The 3D technology enables the user to detect depth & position of features and defects inside concrete that are not visible on the surface. The system could revolutionize the way NDT inspections are executed. The development of the project has received funding from the prestigious EU program Horizon 2020 as well as the Research Council of Norway, Innovation Norway and the Regional Research Fund Inland in Norway and the owners.

COBRI 3.0 handheld rolling ultrasound scanner

Main Features

• Typical scan speed 10 cm / sec
• Penetration depth 50 cm
• Real-time 3D video recording
• Dry coupling
• Frequency range ~ 50 – 250 kHz
• Resolution ~ 1 cm
• Detection of cracks, voids, air pockets, delaminations, rebars & technical pipes
• Measurement of concrete thickness in addition to depth & position of features and defects
• Concrete velocity measurement (strength)
• Total Focusing Method in both cross- and along track direction.

From early field test with Ultra Roller demonstrator prototype

Live 3D data

The scan data from the NDT Ultra Roller is shown live in an intuitive user interface. The 3D data visualization makes it easy for the operator to interpret the concrete structures and identify any defects or features in the concrete. A dual interface enables the operator to review the full 3D volume after scanning (zoom, scan, rotate etc), while at the same time having access to the volume sections as B-scans, C-scans or D-scans. This increases clarity to speed up inspection time and reduce errors in interpretation. Recorded data can be stored, reviewed and sent to clients and colleagues. Potential users are anyone involved in concrete inspection and quality control, such as construction companies, concrete production and rehabilitation companies, as well as universities and research institutions. Road and subway companies, dams and power plant companies, real estate companies, insurance companies, building preservation offices, water and sewerage departments as well as border, security and custom control could also have an interest in the system.

Intuitive  2D and 3D data visualization

Live demonstration on a concrete block with air cavity at the 2018 European Conference on NDT (ECNDT) in Gothenburg, Sweden.


Elop’s patented ultrasound technology is based on an innovative broadband transducer design suited for low frequency applications using a multilayer piezoelectric polymer material, PVDF. The use of separate transmitter (Tx) and receiver (Rx) rollers ensures that the reflection from transmitted pulses against the concrete surface will not interfere with the receiving signals on the other roller. The system is able to send and receive signal waves at any chosen time as coupling between the transducers and target material is always maintained.

Total Focusing Method

The captured data is processed using Synthetic aperture focusing technique (SAFT). This technique offers a different way of focusing compared to shaping of the transducer or using an acoustic lens. A synthetic aperture imitates a large transducer by sampling its area at many points. SAFT is based on subsequent focusing of the data measured on an aperture to every point of the reconstructed area through superposition of the time records. Compared to A-scan and B-scan techniques, SAFT is able to suppress stochastic noise and help to position the reflectors more accurately in the volume space.

Visualization of the scanning principle using SAFT on a concrete specimen