FF-SB Installation Manual
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/2(tan2°)+C, where
− D is the minimum distance to reflective surface (always greater than 100mm or 3.94 in)
− L is the installed scanning range and C is the additional safety distance.
• Obtain C, the additional safety distance, from local safety agency.
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 safety distance using the following formula:
D = Minimum distance to reflective surface (always greater than 100mm or 3.94 in)
L = Installed scanning range
C = Additional distance may be required by a local regulatory agency.
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
For application help: call 1-800-537-6945
L
=
tan ° + C
D
2
2
Honeywell • MICRO SWITCH Sensing and Control 31