Page 26 - MACHINE TOOLS WORLD - September 2021
P. 26
CASE STUDY METROLOGY SECTION
Draw-wire
sensors in
medical
equipment
Draw-wire sensors with high linearity
for the 3D display of the recordings
are needed in computer tomography.
As in many industrial areas, automation is increasingly found in medical technology. A sensor that measures
and monitors movement is used in numerous applications where devices are being moved automatically. The
measurement results can then be used for position regulation or for assigning to other measurement results,
e.g. for the position of sectional recordings in computer tomography. Draw-wire sensors in particular provide an
outstanding price/performance ratio for these types of tasks. Micro-Epsilon, a measurement technology specialist
from Ortenburg, is a leading manufacturer of draw-wire sensors.
n these applications, long service life, a protractor as the sensor element. The
reliability and compact installation measuring wire is attached to the part to
Isize, combined with high accuracy and be measured and is coiled or unwound
low price are the basic requirements for from the drum during movements. In this
measurement systems. Draw-wire sensors way, the linear movement is converted into
satisfy these requirements extremely well. a rotational one, which is then measured
Ultimately the sensors function in a by the respective angle sensor used.
similar way to a tape measure, however, If the measuring distance reduces, the
the displacement or distance information is measuring wire is automatically wound
not read with the human eye but is output back onto the drum.
as an electrical signal. The force required for this is provided by
As well as the housing, the essential a pre-tensioned main spring. In this way, A view into the design of draw-wire
elements of a draw-wire sensor are the wire tension is so large that any wire sensors. The measuring wire is wound
the spring, drum, measuring wire and sag is therefore minimised, particularly precisely on a drum.
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