The flame detector is used for the supervision of gas flames, yellow- or blue-burning oil flames and for ignition spark proving in intermittent operation.

The QRA4.U is for use with the following types of burner control: LFL... LFE1... LFE10... LGB2... / LGB4... with AGQ1... LME21...A2 / LME22...A2 with AGQ3... LME39...A2 with AGQ3... LME41...A2 / LME44...A2 with AGQ3... LME7... LMV2... /LMV3... LMV5... with AGQ1...