Patent ID: 11961379
Assignee: SIEMENS SCHWEIZ AG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. A smoke detection module comprising:
a light emitter arranged on a circuit carrier;
a spectrally matched photosensor in a scattered light arrangement; and
a measurement chamber attached to the smoke detection unit;
the measurement chamber comprising:
at least a passage for smoke to be detected;
a measurement chamber cover with angular light trap structures on an inside of the measurement chamber, wherein the angular light trap structures are shaped to follow the compact-design principle of a Fresnel stepped lens;
a diaphragm to limit the respective emitted light beam located optically downstream of the light emitter; and
a further diaphragm to limit the respective optical reception area connected optically upstream of the photosensor;
wherein the optical limits are dimensioned in such a way that only a proportion of the area of the part of the measurement chamber cover illuminated by the respective light emitter is in a range of 10% to 40% in the respective optical detection range of the at least one photosensor.