Smoke detector for enclosed spaces with a housing (10) in which a separate
smoke chamber (4) with a
smoke inlet opening (5) is partitioned, in which measuring
electronics are arranged which generate an evaluable measurement
signal when
smoke particles are detected, with at least one IR transmitting
diode (6, 8) arranged in the housing (10), the transmitting signals of which are guided by two spaced-apart, parallel, transparent light-guiding media (2, 3) to at least one IR receiving
diode (7, 9), which is provided for receiving the transmitting signals from the at least one IR transmitting
diode (6, 8), wherein the light-guiding media (2, 3) surround the smoke inlet opening (5), wherein a change in the received transmitting signals at the at least one IR receiving diode (7, 9) indicates at least partial covering of the smoke inlet opening (5) and / or particles in the smoke inlet opening (5) and generates a warning
signal, wherein the smoke
detector is designed such that covers and contaminants on the outside of one of the light-guiding media (2,3) alter the light-guiding properties and also a
signal arriving at one end of the light-guiding medium (2,3) by
coupling out part of the signal at a point on the cover and contaminant.