Siemens QRA4.U is a UV flame detector engineered for pipe mounting, providing normal-sensitivity flame supervision for gas- or oil-fired burner controls by detecting ultraviolet radiation from the flame. It supports a QRA4-NPSM thread adapter to accommodate European pipe threads (G1"), simplifying installation on standard piping and aligning with Siemens burner-management configurations. When mounted correctly, the unit provides IP54 protection (to be ensured through mounting).
