Patent ID: 11940370
Assignee: SENSIRION AG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 25:
26. A particulate matter sensor device for detecting or characterizing particulate matter in a flow of an aerosol sample guided through the particulate matter sensor device, comprising:
an enclosure, the enclosure comprising a primary flow inlet and a flow outlet and defining a flow channel for guiding the flow of the aerosol sample through the particulate matter sensor device from the primary flow inlet to the flow outlet;
a radiation source arranged and configured to emit radiation into the flow channel for interaction of the radiation with at least some of the particulate matter in the flow of the aerosol sample;
a radiation detector arranged and configured to detect at least part of said radiation after interaction with the particulate matter;
a flow modifying device configured to at least locally modify the flow of the aerosol sample, the flow modifying device comprising an additional flow opening for creating an additional flow into the flow channel, wherein the additional flow opening is configured to create the additional flow in such a manner that the additional flow overflows the radiation detector or the radiation source after the additional flow has entered the flow channel, thereby sheathing the radiation detector or the radiation source;
a filter associated with the additional flow opening such that the additional flow is a filtered flow;
a feed line for feeding the additional flow from the filter to said at least one additional flow opening; and
a cover that covers the enclosure, a secondary inlet that is separate from the flow inlet being formed in the cover,
wherein the additional flow opening is supplied by a gas drawn into the particulate matter sensor device from the secondary inlet, and
wherein the filter is flat and sheet-like, extending parallel to the cover.