34
107062-12 EN FR26 GLO 501 Printed in France
How to Calculate Safety Distance (Reflective Surfaces Considered)
REFLECTIVE SURFACES
•
To prevent two optical paths to the receiver, install FF-SB light curtains so there are no reflective surfaces
within the beam angles of the emitter and receiver.
•
Calculate reflective safety distance using formula D = L (tan 2,5
°
), where
−
D is the minimum distance to reflective surface (always greater than 131 mm or 5.16 in)
−
L is the installed scanning range
Failure to comply with these instructions could result in death or serious injury.
Reflective surfaces near the sensing field can cause reflection of the sensing beams and result in two optical
paths to the receiver. The light curtain must be installed so there are no reflective surfaces within the beam
angles of the emitter and receiver. Figure 2-2 illustrates the beam angles.
Calculate the reflective minimum safety distance using the following formula:
D = 131 mm, for scanning distances between 0 and 3 m
D = L x tan 2.5° for scanning distances greater than 3 m
D = Minimum distance to reflective surface (always greater than 131 mm or 5.16 in.)
L = Installed scanning range
The emitter and receiver must have the same protected height and resolution. The emitter and receiver must
be mounted at the same height and aligned with each other (see figure 2-2).
Figure 2-2
Distance from Reflective Surfaces (1)
E
R
2.5
2.5
2.5
2.5
L
D
Distance from Reflective Surfaces
(2)
Type 4
0 (optical axis)
100
200
300
400
500
600
700
800
900
-900
0
1
2
3
4
5
Distance L between emitter and receiver (in m)
Minimum distance to reflecting surface (in mm)
6
7
8
9
10
L
D
-800
-700
-600
-500
-400
-300
-200
-100
Reflecting surface
