A particulate matter sensor device comprising: an enclosure defining a flow channel for guiding a flow of an aerosol sample through the particulate matter sensor device , the enclosure defining a primary flow inlet into the flow channel ; a radiation source for emitting radiation into the flow channel for interaction of the radiation with particulate matter in the aerosol sample in the flow channel ; a radiation detector for detecting at least part of said radiation after interaction with the particulate matter; and at least one additional flow opening arranged and configured to create an additional flow into the flow channel so that it sheaths the radiation detector and/or the radiation source , wherein the particulate matter sensor device comprises a filter for filtering the additional flow, characterized in that the particulate matter sensor device comprises an environmental sensor disposed in a flow path of the additional flow upstream of the additional flow opening and downstream of the filter , the environmental sensor being configured to determine at least one environmental parameter, the at least one environmental parameter being at least one of: a temperature; a humidity; and a concentration of one or more target gases, in particular, a concentration of a mixture of gases or a concentration of one or more individual gases, in that the radiation detector is arranged in a flow path of the additional flow downstream of the environmental sensor , and in that the radiation detector and the environmental sensor are mounted on a common circuit board . an enclosure defining a flow channel for guiding a flow of an aerosol sample through the particulate matter sensor device , the enclosure defining a primary flow inlet into the flow channel ; a radiation source for emitting radiation into the flow channel for interaction of the radiation with particulate matter in the aerosol sample in the flow channel ; a radiation detector for detecting at least part of said radiation after interaction with the particulate matter; and at least one additional flow opening arranged and configured to create an additional flow into the flow channel so that it sheaths the radiation detector and/or the radiation source , wherein the particulate matter sensor device comprises a filter for filtering the additional flow, characterized in that the particulate matter sensor device comprises an environmental sensor disposed in a flow path of the additional flow upstream of the additional flow opening and downstream of the filter , the environmental sensor being configured to determine at least one environmental parameter, the at least one environmental parameter being at least one of: a temperature; a humidity; and a concentration of one or more target gases, in particular, a concentration of a mixture of gases or a concentration of one or more individual gases, in that the radiation detector is arranged in a flow path of the additional flow downstream of the environmental sensor , and in that the radiation detector and the environmental sensor are mounted on a common circuit board . a temperature; a humidity; and a concentration of one or more target gases, in particular, a concentration of a mixture of gases or a concentration of one or more individual gases, in that the radiation detector is arranged in a flow path of the additional flow downstream of the environmental sensor , and in that the radiation detector and the environmental sensor are mounted on a common circuit board . <EOS>