Page 35 - ITAtube Journal 3 2025

Press releases
GL Control GmbH
Inner geometry and straightness
of pipes
Circular Triangulation Sensor “CiTriS”
Using the Circular Triangulation Sensor
(CiTriS, see Fig. 2) from GL Control GmbH,
the inner geometry of tubes, pipes, tanks
and other cavities can be measured. The
radial laser beam measures the inner
geometry around 360° in 3600 angle steps.
The result is a precise inner cross section,
and a 3D-model of the inner surface profile
can be generated from the data obtained.
Using this technology, the verification of
tolerances is easy.
The sensor, which has no rotating parts,
projects a 360° radial laser beam on the
target inner surface and measures the
contour. The projected laser line is imaged
by a high-resolution image sensor. Using
image analysis, the 2D contour of the cross
section is created. In a single scan 3600
radii along the circumference are measured
with a speed of up to 60 scans per second.
The resultant radial resolution is 10µm.
Operating at 60 scans per second, a 10
m pipes can be inspected in 180 seconds
with over 10000 cross sections. More than
38 million measurement points provide a
detailed surface inspection.
Depth determination
To correlate the measured cross sections
with the axial position of the scanner inside
the pipe, a distance signal is used to trigger
sensor measurements.
Fig.1 3D inspection system “Crawler”
The distance signal can be produced by an
encoder. Each movement of the sensor will
trigger a cross sectional measurement. The
integration of the encoder with the scanner
is dependent upon the deployment method
of the scanner. When mounting the CiTriS
on a roller skid, the encoder can be mount-
ed on a measuring wheel. In the case of
small-bore holes and operation with sliding
Fig. 2: Circular Triangulation Sensor (CiTriS)
ITAtube Journal December 2025 35