Thursday, November 19 ‧ 10 AM–4 PM ‧ RX Solutions Open Day: Discover Industrial X-Ray CT in Annecy Register
Dimensional measurementhigh-precision 3D industrial metrology with CT

Dimensional measurementhigh-precision 3D industrial metrology with CT

Get a quote
HomeApplicationsTechnical needIndustrial CT Metrology
Dimensional measurements by CT
Titanium dental implant – 150 kV – 12 µm
X-ray CT extends industrial metrology to internal surfaces: it reconstructs your components in 3D, without destroying them, and measures their dimensions and tolerances. Unlike conventional methods, CT offers a complete view that allows internal and external geometries to be characterised simultaneously.
 


What is metrology?

Metrology is the science of measurement. It defines the concepts, methods and reference standards that  guarantee the accuracy, repeatability and traceability of measurement results, with a clear expression of the associated uncertainty. 
 
In the industrial environment, metrology is a cornerstone of quality control. It involves mastery of measurement units, assessment of uncertainties, implementation of calibration procedures, traceability of measurements, and compliance with international standards.
For CT, practices are based in particular on R&R-type studies and recognised reference standards such as VDI/VDE 2630, which provide a framework for the implementation and comparability of results. Discuss my dimensional measurement project 
<strong>Metrological precision </strong><br><br>Results compliant with the VDI/VDE 2630 standard with the Metrology Serieses-image
Metrological precision

Results compliant with the VDI/VDE 2630 standard with the Metrology Serieses
<strong>A single scan </strong><br><br>Replaces dozens of traditional measurements-image
A single scan

Replaces dozens of traditional measurements
<strong>Inside &amp; outside </strong><br><br>Simultaneous measurement of internal and external geometries-image
Inside & outside

Simultaneous measurement of internal and external geometries
<strong>Non-destructive </strong><br><br>No need to cut the part to take internal measurements-image
Non-destructive

No need to cut the part to take internal measurements

Industrial metrology techniques

Coordinate measuring machine (CMM – tactile probing)

Uses a physical probe that touches the surface of the part to capture XYZ coordinates. The probe moves along 3 axes (X, Y, Z) to measure specific points on the part.

 Advantages 

  • Granite base: stability and traceability
  • High precision: 1 µm
  • Versatility: many types of probe
  • Accessibility: deep holes

 Limitations  

  • Point-by-point measurement: ~300–500 points per cycle
  • Deforms soft or thin parts: risk of local deformation
  • Surface access required: hidden/internal features remain inaccessible.
Coordinate measuring machine with tactile probe

Optical 3D scanning (laser)

Projects light patterns (laser lines or structured light) onto the surface of the part. Cameras capture the distortion to reconstruct the 3D geometry. Non-contact measurement. Ideal for large parts.
Optical 3D laser scanner

 Advantages 

  • Speed: complete surface scanned in a few minutes
  • High density: millions of points scanned
  • Non-contact: no deformation.
  • Compact: portable system

 Limitations 

  • Surface only: no internal data
  • Lower precision: than CMMs (20–50 µm)
  • Material-sensitive: may require a spray or powder coating.
 

Vision measuring system (Vision CMM)

High-resolution cameras with calibrated optics. Edge-detection algorithms calculate the dimensions. Often combined with confocal sensors for the Z axis.

 Advantages 

  • Speed: 2D measurements
  • High XY precision: 2–10 µm
  • Ideal for edges/diameters
  • Ideal for transparent parts


 Limitations  

  • Limited Z precision
  • No true 3D capture of the surface
  • Direct line of sight only: hidden/internal features inaccessible.
Vision measuring system

Portable CMM measuring arms

Articulated arms with angular encoders at each joint. Brings the measurement to the part. Can integrate a probe, a scanner or both.
Portable articulated measuring arm

 Advantages 

  • Portable: on-site inspection
  • Multi-sensor: probe + scanner
  • Reach: 1.2 to 4.5 m


 Limitations 

  • Lower precision: 20–80 µm
  • Operator-dependent
  • Thermally sensitive
  • Cumulative angular errors

 

Comparison of metrology methods



Tactile CMM
3D optical scanVision systemPortable CMM measuring arm3D CT
Accuracy1-2 µm20-50 µm2-10 µm20-80 µm5 µm
Data density300-500 pointsMillions of pointsThousands of pointsVariableMillions of points
ContactPhysicalNo contactNo contactDepends on configurationNo contact
Access to internal featuresLimited (deep holes)Surface onlyDirect line of sight onlyLimited Yes
Best applicationsMaximum precision required, critical dimensions
Complex surfaces, reverse engineering, large parts
2D features, small parts, electronics / PCBs
Large shopfloor assemblies
Internal inspection



Discuss my metrology needs

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send
 


Why combine metrology and CT?

Industrial CT represents a natural and major evolution for metrology: used in measurement mode, it transforms the CT system into a CMM (coordinate measuring machine) equipped with a volumetric sensor.

The objective is no longer limited to inspection (defects, porosity, assemblies): it involves dimensional measurements and validation of tolerances on both internal and external surfaces, even in areas inaccessible to conventional probes or optical means, without damaging the part.

A single scan produces a complete 3D volume that serves as a single dataset for dimensional control and reporting, while enabling simultaneous analysis of even highly complex internal and external geometries.
 

Why choose CT for your metrological measurements?

High-precision 3D inspection – inside and out. Industrial CT offers unrivalled capabilities for dimensional metrology:

  • Non-destructive, fully 3D measurements, including on internal features
  • High accuracy and repeatable results, with an MPE SD of 5.5 µm + L/50 depending on the configuration
  • A single scan replaces dozens of traditional measurements
  • Ideal for complex geometries
  • Ideal for checking assemblies without disassembly, making it possible to measure positioning, clearances and dimensions under real constraints
  • Ideal for comparing a part with its CAD file and validating a process
  • Non-contact: suitable for deformable parts
  • Suitable for transparent or shiny parts, without preparation (powdering, markers, etc.)

With RX Solutions CT metrology solutions, benefit from a state-of-the-art CT platform designed to deliver high-precision measurements every day.

Metrological applications using CT

Three-dimensional measurement by CT

Determining the geometry of samples with great precision in a single, fast scan.
Whatever the complexity of the shapes, CT generates a high-density 3D point cloud from which all traditional measurements can be made: geometric and positional tolerances (parallelism, perpendicularity, circularity, concentricity, coaxiality, etc.). Non-contact and non-destructive, the method suits a wide range of industrial components. With results down to the micron depending on the configuration, CT becomes essential to qualify and inspect complex parts and assemblies.

Nominal-to-actual comparison

A typical task performed with a CT system certified for metrology (see the Metrology Series) is the 3D nominal-to-actual comparison, visualising the geometric deviations between the data extracted from a scan of a part and its digital model.

This comparative metrological analysis enables:
  • Rapid sample qualification, with deviation mapping at all points and colour visualisation of deviations
  • Continuous improvement of production processes (injection moulding, 3D printing, machining)
  • Complete metrological traceability for quality certification
  • Validation of tolerances on complex parts that are impossible to measure otherwise
  • Correction of moulds or CAD models for additive manufacturing, thanks to calculation models that take into account the actual deformations of the parts produced

Deviations are shown in a colour code that gives an immediate and precise overview of the differences between the parts being compared, facilitating decision-making and the optimisation of production parameters.
CAD comparison by CT
Ideal CAD file
CAD comparison by CT
Scan of the real part
CAD comparison by CT
3D analysis
CAD comparison by CT
Deviation calculation


Discuss my CT needs

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send
 


The platforms for dimensional measurement

Two platforms offer 6 configurations compatible with the Metrology Series, to be adjusted according to the available space and the size and weight of your parts. The Explorer, Nano and Force lines can be customised with the Series.

Compatibility table (Metrology Series on EasyTom S and EasyTom L; Explorer: S, L; Nano: L, UltraTom; Force: L, B): 


Product lines
EXPLORER
NANO
FORCE
Platforms
EasyTom S
EasyTom L
EasyTom XL
EasyTom B
EasyTom L
EasyTom XL
UltraTom
EasyTom L
EasyTom B
Series
Metrology Series



Fab Series





Performance
Resolution
         
         
         
         
         
         
         
         
         
Sample density
         
         
         
         
         
         
         
         
         
EXPLORER EasyTom S
Series
Metrology Series   
Fab Series   
Performance
Resolution            
Sample density            
EXPLORER EasyTom L
Series
Metrology Series   
Fab Series   
Performance
Resolution            
Sample density            
EXPLORER EasyTom XL
Series
Metrology Series  — 
Fab Series   
Performance
Resolution            
Sample density            
EXPLORER EasyTom B
Series
Metrology Series  — 
Fab Series  — 
Performance
Resolution            
Sample density            
NANO EasyTom L
Series
Metrology Series   
Fab Series  — 
Performance
Resolution            
Sample density            
NANO EasyTom XL
Series
Metrology Series  — 
Fab Series  — 
Performance
Resolution            
Sample density            
NANO UltraTom
Series
Metrology Series   
Fab Series  — 
Performance
Resolution            
Sample density            
FORCE EasyTom L
Series
Metrology Series   
Fab Series  — 
Performance
Resolution            
Sample density            
FORCE EasyTom B
Series
Metrology Series   
Fab Series  — 
Performance
Resolution            
Sample density            
EasyTom S
EasyTom S
EasyTom L
EasyTom L
EasyTom S
The EasyTom S is the compact platform of the Metrology Series, designed for small samples (up to Ø 300 × 410 mm and 5 kg) with a minimal footprint, without compromising image quality. It is available in the EasyTom S 150 configuration with a 25x32 detector for an MPE of 5.5 µm + L/50 (VDI/VDE 2630-1.3).

N° of axes: 4+2
Max SSD: 612 mm
Max scan volume: Ø 230 mm x H 380 mm
Max resolution: 5 µm (en configuration Metrology Series)

Sample
Max sample size: Ø 300 mm x 410 mm
Max sample weight: 5 kg
Internal loader 6: Ø 45 mm x H 155 mm
Internal loader 3: Ø 175 x H 155 mm

General 
Weight: 1020 kg
Dimensions: 1345(W) x 900(D) x 1870(H) mm
×
EasyTom L
The EasyTom L covers a wide range of part sizes, from small technical components to assemblies of over a metre. Five configurations are compatible with the Metrology Series: EasyTom L 230, 300 and 450, with a 25x32 or 43x43 detector depending on the model, for an MPE of 5.5 to 6 µm + L/50 (VDI/VDE 2630-1.3).

N of axes: 6+2
Max SSD: 1015 mm
Max scan volume: Ø 500 mm x H 580 mm
Max resolution: 4 µm

Sample
Max sample size: Ø 685 mm x 900 mm
Max sample weight: 30 - 80 kg kg
Internal loader 6: Ø 70 mm x H 220 mm
Internal loader 3: Ø 120 x H 220 mm

General 
Weight: 3700 kg - 5850 kg
Dimensions: 2400 (W) × 1200 (D) × 2000 (H) mm
×

EasyTom S configuration and MPE


EasyTom S 150 — Flat panel 25x32 : VCI/VDE 2630-1.3 MPE SD : 5,5 µm + L/50

EasyTom L configurations and MPE


EasyTom L 230 — flat panel 25x32 : VCI/VDE 2630-1.3 MPE SD : 5,5 µm + L/50
EasyTom L 230 — flat panel 43x43 : VCI/VDE 2630-1.3 MPE SD : 6 µm + L/50
EasyTom L 300 — flat panel  25x32 : VCI/VDE 2630-1.3 MPE SD : 5,5 µm + L/50
EasyTom L 300 — flat panel  43x43 : VCI/VDE 2630-1.3 MPE SD : 6 µm + L/50
EasyTom L 450 — flat panel  43x43 : VCI/VDE 2630-1.3 MPE SD : 5,5 µm + L/50

Discover the 3 RX Solutions lines: Force - Explorer & Nano


Dental part scanned by Explorer micro-tomography Aerospace part in metal additive manufacturing 

EXPLORER

Versatile micro-tomography

2 µm RESOLUTION
300 kV SOURCE VOLTAGE
< 1 µm MIN. VOXEL

Reveal the invisible at the micron scale.

Access the finest microstructures, porosities and interfaces with a resolution down to the nanometre scale.

Platforms Easytom S · Easytom L · Easytom XL · EasyTom B
 Discover the Explorer line      
Microscopic structure analysed at nanometric resolution Life sciences, Wood

NANO

Nanometric analysis

250 nm RESOLUTION
160 kV SOURCE VOLTAGE
30 nm MIN. VOXEL

Reveal the smallest details with nanometric precision.

Nanometric resolutions to characterise microstructures, porosities and interfaces at a scale that optical microscopy cannot reach.

Platforms Easytom L · Easytom XL · Ultratom
 Discover the Nano line      
Electronic component inspected by Force high-energy tomography Titanium additive manufacturing injector 

FORCE

High-energy solution

4 µm RESOLUTION
450 kV SOURCE VOLTAGE
250 kgs Load up to

See through the densest materials.

Inspect thick metal parts, complex assemblies and highly absorbing components with optimal image quality.

Platforms Easytom L · Easytom B
 Discover the Force line      

A metrological custom-made solution, designed with you

If no standard platform matches your needs exactly, we can look at a custom project together. From a simple adaptation of an existing platform to a completely unique design, our teams work in collaboration with yours to design the CT system that will meet your applications precisely.
Discover custom-made CT systems

Dimensional measurementsWhy work with RX Solutions for your dimensional measurements?

At RX Solutions, all our teams are 100% dedicated to CT. From standard to custom projects, we have the solution that will meet your specific application precisely.
01

Manufacturer for over 20 years

We have been designing and building our CT systems in France for over 20 years. This direct expertise allows us to offer you the most suitable configuration, without depending on an intermediary.
02

A modular line

Force, Explorer, Nano or a custom configuration: our line covers a broad spectrum of industrial applications, with the option of adapting each platform to your specific constraints.
03

Complete technical support

Installation, training for your teams, preventive maintenance: we support you well beyond delivery of the machine to guarantee its long-term performance.
04

An international distributor network

Wherever you are, our distributor network provides local support, in your language and in line with local practices.


Discuss my dimensional measurements. CT needs

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send
 


 Dimensional measurementsFAQ: What you need to know about dimensional measurement by CT

Can computed tomography (CT) really measure, or does it just ‘see inside’?
Yes. Industrial CT is more than an image: it provides a complete 3D volume in a single scan, from which dimensional measurements can be made on internal and external surfaces, with tolerances and GD&T.
How reliable is CT for 3D measurements?
Reliability depends on the system, its settings and the metrological procedures. RX Solutions ‘Metrology Series’ CT systems specify an MPE compliant with VDI/VDE 2630 and make it possible to calculate task-specific uncertainty. With periodic calibration and checks, repeatable and traceable measurements are obtained.
Does CT replace a CMM?
CT complements the CMM. CT measures inaccessible geometries (cavities, assemblies, internal areas) without contact; tactile CMM remains relevant for certain critical dimensions and tight tolerances, depending on materials and geometries. In practice, CT and CMM are often combined.
What are the gains compared with a CMM or optical vision?
We move from point-by-point inspection to the analysis of a complete volume:
  • access to hidden geometries without cutting,
  • a single scan replaces several operations,
  • dense point cloud for all dimensions and CAD/scan comparison,
  • less preparation and clamping, more speed on complex parts.
How long does a CT scan or measurement take?
It depends on the size, material/density, thickness and resolution required. Allow from a few minutes to over an hour. Automation (sample loader, scheduling, recipes) makes it possible to run batches 24/7, with automatic reports.
Do artefacts (rings, beam hardening) distort measurements?
They can. They are reduced by suitable parameters (kV, filters), trajectories and software corrections. The residual effect is then validated through measurement uncertainty and reference parts, to guarantee metrological accuracy.
How does the nominal-to-actual comparison (CAD ↔ scan) work?
The scanned part is aligned to the CAD model (best-fit / DRF), the 3D deviations are calculated, a colour deviation map is displayed and the GD&T dimensions are extracted. The results are traced in reports (PDF/CSV/QIF) and integrated into SPC.
What is the MPE of a CT system?
The maximum permissible error according to VDI/VDE 2630-1.3, for example ‘5.5 µm + L/50’ for the EasyTom L 230 with a 25x32 detector.
Which configurations are compatible with the Metrology Series?
Two platforms and six configurations: EasyTom S 150 and EasyTom L 230, 300 and 450.

Want to keep in touch?

Send
By subscribing to the newsletter, you agree to receive personalised marketing communications by email, and confirm that you have read the privacy policy.