SG4 BASE
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2.2.2
Distance between homologous devices
The following graphic shows the distance from the interfering devices (Ddo) according to the operating distance
(Ddo) of the couple ( TXA
– RXA ).
If different safety devices have to be installed in adjacent areas, the emitter of one device must not interfere
dangerously with the receiver of the other device.
The TXB interfering device must be positioned outside a minimum Ddo distance from the TXA
– RXA emitter-
receiver couple axis.
Fig 15 - Distance between homologous devices
This minimum Ddo distance depends on:
the operating distance between emitter (TXA) and receiver (RXA)
the effective aperture angle of the ESPE (EAA)
Fig 16 - ESPE Type4
The following table shows, for convenience, the values of the minimum installation distances relative to some
operating distances:
Operating distance (m)
Minimum installation distance (m)
3
0,3
6
0,4
10
0,5
19
0,6
The interfering device (TXB) must be positioned at the same Ddo distance, calculated as
shown above, even if closer to TXA respect to RXA.
Installation precautions have to be taken to avoid interference between homologous
devices. A typical situation is represented by the installation areas of several adjacent
safety devices aligned one next to the other, for example in plants with different
machines.
