schmersal SLC 410 B Instructions De Montage Et De Raccordement page 65

DISTANCE BETWEEN REFLECTING SURFACES
The presence of reflecting surfaces in proximity of the photoelectric light curtain may
generate spurious reflections that prevent monitoring. With reference to Figure 25, object A
is not detected because surface S reflects the beam and closes the optical path between the
Emitter and Receiver. A minimum distance d must therefore be maintained between any
reflecting surfaces and the protected area. The minimum distance d must be calculated
according to the distance l between the Emitter and the Receiver, considering that the angle
of projection and reception is 4°.
Figure 26 illustrates the values for the minimum distance d that must be maintained when
the distance l between the Emitter and Receiver is changed.
After installing the system, check whether any reflecting surfaces intercept the beams, first in
the centre and then in the vicinity of the Emitter and Receiver. During these operations, the
red LED on the Receiver should never, for any reason switch off.
Figure 25
Figure 26
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