MICRO-EPSILON scanCONTROL2800, Инструкция по эксплуатации

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MICRO-EPSILON
X9751109-B060097MSC 32
Information for Operation
8.4 Error Effects
8.4.1 Degree of Reflection on the Target Surface
Basically, the sensor evaluates the diffuse portion of the reflections of the point of laser
light. Any statement about a minimum degree of reflection is only possible with
restriction.
A preliminary examination is needed for application of the sensor on transparent or
mirrored targets. The method of direct reflection on mirrored surfaces, as applied
successfully during point triangulation, cannot be used with line triangulation due to the
fan shape of the laser lines (central projection). Here, only a narrow region near the
center would reach the receiver objective lens. In addition, since with profile
measurement usually curved surfaces are to be measured, this region is narrowed even
further.
8.4.2 Color Differences
Color differences on targets have an effect. Often however, these color differences are
also associated with different penetration depths of the laser light into the material.
Different penetration depths lead in turn to apparent changes in the line intensity.
Consequently, changes of color, associated with changes in the penetration depth, can
lead to measurement uncertainties.
Since the illumination parameters can only be changed overall for a profile, careful
matching of the exposure to the target surface is recommended.
8.4.3 Temperature Effects
During initial operation, a warm-up time of at least 20 minutes is required in order to
achieve a constant spread of temperature in the sensor.
If measurements are being taken in the μm accuracy range, the effect of temperature
variations on the sensor mounting must be taken into account by the user. Fast
temperature changes are only acquired with delay due to the damping effect of the
sensor's thermal capacity.
8.4.4 Extraneous Light
An interference filter is provided in the sensor for the suppression of extraneous light,
together with an adjustable detection threshold in the controller.
Generally, screening of extraneous light shining directly onto the target or reflecting
into the sensor must be ensured by guard walls, etc. In addition, the application of the
higher laser power of 15 mW (Laser Class 2M) is recommended, for which however no
extra laser safety measures need to be taken.
Pay particular attention to undesired reflections of the laser line outside of the target
area (background, target holder, etc.), which can be reflected back into the receiver's
line of sight. For all objects outside of the measurement range (target holder, transport
equipment, grippers, etc.), matt black surface coatings are recommended.
8.4.5 Mechanical Vibrations
If high resolution in the μm range is to be obtained with the sensor, special attention
must be paid to the stable and vibration-damped mounting of the sensor and target.