SMARTSCAN 072-150, Handbook

Page: 46 / 55

7 0 0 0 S E R I E S
Positioning the light curtain
The following points should be considered before final selection of a
light curtain.
q The position of the light curtain in relation to the danger point,
particularly the separation distance (S).
q
The stopping performance of the machine together with the response
time of the safety system (t1+ t2).
To assist with the selection of a Smartscan light curtain for a specific
application refer to the following information which has been taken from
European Standard BS EN 999.
Detection capability - the dimension representing the minimum
diameter of an opaque cylinder which, when placed into the light
curtain, at any angle to the detection plane, is guaranteed to actuate the
light curtain.
Separation distance (S) - The distance along the direction of
approach, between the outermost position at which an appropriate
opaque object is detected and the nearest hazardous part.
Abbreviations:
S = separation distance (mm)
H = height of the light curtain above the reference plane (mm)
e.g. floor
t1 = response time of light curtain and control unit (secs)
t2 = stop time of machine (secs)
The detection zone of the selected light curtains must be of a length to
prevent access to the hazard from either over or underneath the light
curtain. If necessary install additional mechanical guarding to prevent
access into the hazardous area.
APPENDIX 1 44