etro lo g y - Carl Zeiss

Metrotomography: Computed Tomography
and Metrology in One
Stephan Klumpp
Fig. 1:
The new ZEISS Metrotom
instrument
6
The term metrotomography is the
result of combining metrology
and tomography. The fusion of
industrial metrology and industrial
computed tomography (CT) will
present comprehensive quality
assurance with even more unknown
possibilities.
As a supplement to traditional
technologies in testing and measuring
technology, industrial computed
tomography is conquering new fields
of application with fascinating and
very productive solutions.
The possibility of completely
capturing a part and thus assessing
the interior and exterior provides the
user with all evaluation possibilities
at a glance – within a short time and
without destroying the component.
Carl Zeiss 3D Metrology Services
GmbH in Aalen, Germany performs a
fast-growing number of CT services
for a wide variety of applications
in industrial testing and measuring
technology.
Customers are amazed at the results
and the simple methodology.
Metrotomography
applications
The main applications are concentrated
in the following areas:
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Destruction-free testing:
- Defect checks
- Porosity analyses
- Assembly inspection
- Damage analysis
- Inspection of materials
Dimensional metrology
Reverse engineering
Comparison of geometries
Potential
and challenge
Technologists for metrology and
metrotomography at Carl Zeiss, Dr.
Dietrich Imkamp and Dr. Hubert
Lettenbauer, summarize the challenges
of metrotomography as follows:
“Dimensional measuring is more than
just quantifying 3D image data. The
quality of this data, the result of a CT
scan in this case, largely depends on the
quality of the entire chain of recording
and thus from several parameters
(size of the focal point, stability of the
tube voltage, quality of the overall
kinematics, etc.). Mastering this chain,
as well as suitable calibration methods,
is the first step in creating high-quality
image data.”
The same applies to the subsequent
evaluation of the data. The orientation
of the object according to the drawing,
the inspection of form and position
and the determination of curve gaps
or the display of surface forms in
accordance with DIN are everyday
tasks in coordinate metrology.
All these demands apply to CT, the
same as with traditional measuring
equipment. However, the deciding
factor for users is reliable information
on whether the measured features of
their part to be measured are within
specified tolerances nor not. Trusting
any results without verification of
measuring system analysis is not only
negligent regarding the quality of the
product to be measured. 3D CT would
also lose acceptance at an early stage
of its development as specialists usually
recognize such deficits quickly.
Only someone able to master the
entire measuring chain is capable of
delivering and verifying reliable and
reproducible results. The benefit to
the user from the CT data is significant
and offers enormous potential for the
future of this technology.
Innovation SPECIAL Metrology 8, 006