Bei der Erfindung handelt es sich um einen Streulichtrauchmelder, der bei einem Selbsttest die Verschmutzung von Raucheintrittsöffnungen und einem Insektengitter erkennt.
The detector (1) has a measuring light transmitter (4) provided in a measuring chamber (3) for transmitting light into the chamber. A diffused light test receiver (5) receives the light emitted by the transmitter. A diffused light measuring volume (19) is provided in the chamber with a labyrinth. A detector housing and the chamber are partially manufactured from a material with shiftable optical characteristics. The shiftable material that fulfills function of shiftable panel is not arranged between the transmitter or the receiver and the measuring volume. Independent claims are also included for the following: (1) a method for manufacturing a smoke detector (2) a method for detecting contamination of a smoke inlet opening and/or insect grid of a detector (3) a method for coloring a detector.