For monitoring the flame of Kromschroeder burners of any power, with or without blowing, in heating furnaces, furnaces, industrial furnaces and combustion plants with continuous operation. Kromschroeder burners can be ignited directly or operated as a pilot and main burner for a Kromschroeder. UVD 1 can only be operated in conjunction with a Kromschroeder burner control unit type BCU 460-480..U or PFU..U.