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Angled approach:
If the direction of approach and the detection plane forms
an angle, the following applies:
• If the angle α is greater than 30°, then the approach is
considered as a normal approach (see above mentioned
formula)
• If the angle α is smaller or equal to 30°, then the
approach is considered as a parallel approach (see
above mentioned formula)
Note 1
If a possible access from the top, the bottom or laterally
can be foreseen, additional guards must be installed.
Particularly, if the distance S1 between the table and the
barrier is greater than 100 mm, the photoelectric barrier
must be supplemented by a solid screen. According to
the EN 294 norm, this solid screen must be:
- fixed, i.e. fitted with the aid of a tool or welded if
disassembly is not necessary,
or
- automatically positioned and checked if opening is
necessary.
In this case, it must be impossible for the operators to
neutralize the position sensors.
Positive break safety switches from Honeywell may be
used with mechanical barriers as part of circuit.
Note 2
If the tool can be changed (for instance in a press),
calculate the distance "S" based on the tool that is the
most bulky.
4
Note 3
It is most important that if distance "S" is large, it must
not be possible for the operator to stay undetected
between the safety barrier and the danger zone from
above, below or laterally.
Penetration into the danger
Penetration into the danger
zone under the barrier
zone above the barrier
Penetration between the
Mechanical protection on the
barrier and the danger zone
rear face and on the sides
Reflecting surface
The beam angle of the optics and the alignment
tolerance for emitter and receiver are approximately 2°.
Since reflecting surfaces within the detection zone can
lead to deflection and therefore non-detection of an
obstacle, a minimum distance D to the optical axis
should be observed. For a distance L between emitter
and receiver, according to the pr 50 100 - 1/2 norm, the
following applies:
D = 100 mm, for 0 < L ≤ ≤ ≤ ≤ 3 m
D = 0,035 L/2 + 5 (mm) for 3 < L ≤ ≤ ≤ ≤ 24 m
For L = 10 m, D = 180 mm
Minimum distance
2˚
Emitter
2˚
Scanning distance L
Reflective surface
D
2˚
Receiver
2˚
107026-11-EN FR26 ROW 302 Printed in France
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