News

Metrology Partnership project on industrial computed tomography feeds into published standard

Measuring a hole just 63 microns wide with a contact style CMM - a metrology miracle! Courtesy of METAS

Measuring a hole just 63 microns wide with a contact style CMM - a metrology miracle! Image: Courtesy of METAS

Supporting the digital transformation in Europe by monitoring the detail detection sensitivity of iCT measurements

Industrial Computed Tomography (iCT) is a scanning technology with growing use in different sectors such as the automotive and aerospace industries. The detail detection sensitivity of iCT systems is evaluated by human operators - which can be unreliable and costly. There is a need to develop traceable measurement and monitoring methods for determining the detail detection sensitivity of iCT systems and its standardisation.

Metrology partnership project Advanced detail sensitivity monitoring by new concepts to improve the reliability of safety relevant products using industrial computed tomography (23NRM05, SensMonCT II) aims to address this need through the development of:

novel traceable test gauges to be measured by iCT systems
evaluation algorithms, which will increase the reliability of the measurements of iCT detail detection sensitivity

By developing automated detail detection sensitivity monitoring for iCT systems, the project will provide the necessary metrological reliability of iCT in industry, including the automotive and aerospace sectors, and help to improve the safety of their products. Further to this, the project’s results will be disseminated to relevant standard organisations such as ASTM, CEN and ISO, in order to support their incorporation into standards.

Standard published

The work of this project has fed into the newly published standard ASTM E 3505-25 (July): Standard Practice for Direct Determination of Computed Tomography (CT) Detail Detection Sensitivity and Calculation of Numerical Detection Limit.

Software “StudioMax” of project partner VolumeGraphics was revised to comply with this standard – in June 2025 an update of the analysis tool for ASTM E1695/E1441 was published.

Software

The consortium has developed the first stand-alone comprehensive software for calculation of Modulation Transfer Function / Contrast Discrimination Function / Contrast Detail Diagram and the detail detection sensitivity (DDS). After further testing, software will be available for download at the project website.

Prototypes

New state of the art test gauges have been manufactured using modern subtractive and additive manufacturing and lithography. The test gauges have been manufactured in different scales to cover a large range of applications. These include electronics (μm), casting (mm), and small and large assemblies (cm).

In addition, the gauges will be measured and evaluated for their functionality with the new advanced automated digital evaluation algorithms, based on the analysis predicting the visibility of details.

Newsletter

This Newsletter gives full details of the project concept, theory and activities.

Project coordinator Marko Katić from FSB-LPMD in Croatia said

‘Developing standardised test gauges for CT, which is an inherently multiscale process, was a significant challenge at the time this project was started. We are happy to report that members of our consortium have successfully met this challenge and managed to establish manufacturing technologies that can produce high aspect ratio holes with very high dimensional accuracy, while avoiding prohibitive costs of manufacturing – that’s an achievement which we believe will have an impact beyond this specific area. Just for reference, the smallest gauges have an outer diameter of 0.45 mm and contain different hole sizes with the smallest holes having a diameter of only 600 nm. At the same time, gauges with an outer diameter of 50 mm and 1 mm thickness have also been made - having a smallest hole diameter of 80 µm - with similar relative accuracy.’

This Metrology Partnership project has received funding from the European Partnership on Metrology, co-financed by the European Union Horizon Europe Research and Innovation Programme and from the Participating States.

Want to hear more about EURAMET?