Flame safeguard with approval for continuous operation for the supervision of oil
flames and gas flames in applications with an ionization probe and a photocell
detector RAR9.
Flame safeguard for intermittent operating mode with UV flame detectors QRA2 /
QRA4 / QRA10.
LFS1 and this Data Sheet are intended for OEMs using the LFS1 in or on their
products

LFS1 units are designed for the supervision of oil burners and gas burners in
combination with control unit LEC1 or with programmable logic controllers.
Typical fields of application range from industrial burners up to the highest security level
SIL3 and in the field of ship burners.
Flame supervision:
-  takes place with photocell detector RAR9 with approval for continuous operation, in
the case of LFS1.1
-  takes place with an ionization probe with approval for continuous operation or with
UV flame detector QRA2 / QRA4 / QRA10 in intermittent operation, in the case of
LFS1.2
Excluded are the types QRA2M and QRA10M.