Abstract: An air purifier (10) uses an air purifier filter unit (12) and a sensor (26) for sensing the matter to be filtered by the air purifier filter unit. By monitoring (18) the performance of the air purifier combined with information about the air purifier filter unit, it is possible to determine a volume of the space in which the air purifier (10) is deployed.

Abstract: An air purifier comprise a gas filter between an upstream air flow and a downstream air flow and a concentration sensor comprising a first electrode and a second electrode, the first electrode being exposed to the upstream air flow and the second electrode exposed to the downstream air flow, the concentration sensor providing an output signal based on the difference in concentrations of a target gas at the first and second electrodes. The output signal is processed to determine information relating to the condition of the gas filter.

Abstract: Presented is a device (100) for filtering air, comprising: an air filter (101) comprising: a first component (102) adapted for filtering air having a humidity level falling within a first humidity level range; and a second component (103) adapted for filtering air having a humidity level falling within a second humidity level range; a control system (106) configured for: receiving a sensed relative humidity of air, and selecting the first (102) or the second (103) component for filtering the air, depending on the sensed relative humidity of the air.

Abstract: An air purifier comprise a gas filter between an upstream air flow and a downstream air flow and a concentration sensor comprising a first electrode and a second electrode, the first electrode being exposed to the upstream air flow and the second electrode exposed to the downstream air flow, the concentration sensor providing an output signal based on the difference in concentrations of a target gas at the first and second electrodes. The output signal is processed to determine information relating to the con- dition of the gas filter.

Abstract: Presented is a device (100) for filtering air, comprising: an air filter (101) comprising: a first component (102) adapted for filtering air having a humidity level falling within a first humidity level range; and a second component (103) adapted for filtering air having a humidity level falling within a second humidity level range; a control system (106) configured for: receiving a sensed relative humidity of air, and selecting the first (102) or the second (103) component for filtering the air, depending on the sensed relative humidity of the air.

Abstract: An air purifier (10) uses an air purifier filter unit (12) and a sensor (26) for sensing the matter to be filtered by the air purifier filter unit. By monitoring (18) the performance of the air purifier combined with information about the air purifier filter unit, it is possible to determine a volume of the space in which the air purifier (10) is deployed.

Abstract: Presented is a chemical formaldehyde filter comprising a filter substrate having a porous structure; the filter substrate comprising a mixture of a formaldehyde absorbent and a porous framework material. Further, a method for fabricating such a filter is described.

Abstract: Embodiments of the present invention relate to freshness indication. In some embodiments, a freshness indicating device is provided. The freshness indicating device comprises a collector and an indicator. The collector is adapted to collect water from an object. The object includes at least one of fruits and vegetables. The indicator is adapted to indicate the freshness of the object based on the amount of the collected water. A corresponding method and a container comprising the freshness indicating device are disclosed as well.

Abstract: The invention provides a wearable air purification device which actively generates a propelled stream of purified air for direct delivery to a region proximal to a user's mouth or nose for their immediate inhalation. An air chamber comprises a flexible diaphragm adapted to fluctuate between two extreme positions, thereby altering the volume within the chamber and alternately sucking and blowing air into and out of the chamber. Filtration elements are arranged in said air chamber. The filtration elements are arranged so as to make fluid communication with air displaced into the air chamber and, to make fluid communication with air displaced out of said chamber so that air is cleaned as it passes both into, and out of, the air chamber. The filtration elements actively remove particulate or gaseous pollutants. Embodiments of the invention may comprise a plurality of such air chamber assemblies, arranged so as to collectively deliver a continuous flow of air to a breathing zone of the user.

Abstract: In various embodiments, an air purification system (100, 300, 400) may include a first air filter (316, 416) that targets at least a first type of pollutant. In various embodiments, air that passes through the first air filter may be unobstructed by other air filters. In various embodiments, a second air filter (316, 416) may target at least a second type of pollutant that is different than the first type of pollutant. In various embodiments, air that passes through the second air filter may also be unobstructed by other air filters. In various embodiments, a controller (102, 302) may be configured to selectively move the first and/or second air filters to expose one or both of the first and second air filters to one or more air streams, e.g., based on user input and/or on one or more signals from one or more pollutant sensors (106, 306).

Abstract: A sensor system is for sensing a substance in a fluid (1), comprising a first sensor (10) and a second sensor (12) of the same type. The first sensor (10) is used until a calibration event, during which the second sensor (12) is used. The second sensor (12) is used only during the calibration event. The first sensor (10) is calibrated using the sensor information from the second sensor (12).

Abstract: The invention provides a solid oxide fuel cell stack, which comprises an upper current collector plate (1), a lower current collector plate (2) and a stack structure (3) accommodated between the upper current collector plate (1) and the lower current collector plate (2), wherein the stack structure (3) includes at least two connectors (11) and a cell plate (12) disposed between the two adjacent connectors (11) which have an anode side and a cathode side. An oxidant gas seal member (13) is provided at the anode side of the connector (11), and a fuel gas seal member (14) is provided at the cathode side of the connector (11). A hermetic oxidant gas supply passage, a hermetic fuel gas supply passage, a hermetic fuel gas discharge passage and open oxidant gas discharge passages are set in the stack structure (3).