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Installing
4.2 Mounting
SITRANS SL
42
Operating Instructions, 12/2010, A5E01132948-04
At installation of the SITRANS SL, the laser and the photo-detector have to be aligned to the
optical axis of the sensor pair. Note that each sensor has an optical axis of its own which is
its axis of symmetry. In addition the sensor body is at an angle to this axis. The reason for
this is that the laser beam passes a wedged window before exiting. This wedge window will
refract the beam approximately 1.5°. The following figure illustrates this.
ar
º
①
Axis of symmetry for sensor (optical axis)
②
Axis of symmetry for sensor body
Figure 4-2
Symmetry axes
The sensors are equipped with a flange pair called process interface to align both optical
axes to one another. In this way an angle error of up to ± 1° on each side can be
compensated.
See also
Service and support (Page 201)