A measuring apparatus includes an input to receive an aerosol sample, a modifier unit to provide a modified sample by removing particles of the aerosol sample, and a sensor unit to measure a spectral profile by detecting molecules of the gas phase of the modified sample,
wherein the spectral profile is a mobility spectrum or a mass spectrometer spectrum, the modifier unit is arranged to generate a corona discharge, to form charged particles by charging particles of the aerosol sample with the corona discharge, and to provide the modified sample by removing the charged particles with an electric field, the particle removal efficiency of the modifier unit has a cutoff size to prevent propagation of particles larger than the cutoff size to the sensor unit, and the cutoff size is in the range of 1 nm to 20 nm.

Provided is an air cleaner that can take a large amount of air in a large space into a dust collector with good efficiency while being lightweight and having easy maintenance. An air cleaner is provided with a drone and a dust collector. The drone has a main body unit and propellers attached to the tips of frames. The dust collector has electric discharge electrodes and a dust collection electrode. The electric discharge electrodes are connected to a booster unit within a central chamber. The booster unit is electrically connected to a control unit in the main body unit. Electric discharge is formed between the dust collection electrode and the electric discharge electrodes, and dust particles in the air are charged and collected by the dust collection electrode.

A cooking fume purification module and a cooking fume exhaust device are provided. The fume purification module includes a housing, a plurality of dust collection plates and an emitter plate. The housing includes a cylindrical body and a plurality of protruding portions. The body defines an air channel. The plurality of protruding portions extends outwards from the body, and each protruding portion defines an introduction channel in communication with the air channel. The emitter plate is arranged on the protruding portion and provided with a plurality of emitter pins which are located in the introduction channel and face the air channel. The plurality of dust collection plates are arranged in the air channel and spaced apart along an axial direction of the body, and each dust collection plate corresponding to one emitter plate.

An ion generating device can include a housing having an opening, an anode and a cathode disposed within the housing and having a space between them in fluid communication with the opening, a power source having a negative terminal and a positive terminal with a first connection between the negative terminal and the anode and a second connection between the positive terminal and the cathode, and an air mover disposed to direct an air flow through the space and out of the opening.

An image forming apparatus includes a flow passage associated with a direction of flow and a particle collecting device including a filter to collect particles in a fluid passing through the flow passage in the direction of flow. The flow passage includes a curved portion, and a distribution in particle collecting performance of the filter in a direction perpendicular to the direction of flow results from the curved portion of the flow passage.

An ionizing arrangement for electrically charging particles in an air flow in an air duct, said air duct including a section B extending along an axis A. The arrangement includes: a shielding electrode intended to be arranged within the air duct, said shielding electrode including: a portion for arrangement in a plane substantially transverse to the longitudinal axis A, said member has a shape corresponding to the cross sectional shape of the duct. The arrangement furthermore includes at least one corona electrode arranged in the center of the portion, wherein the shielding electrode is further arranged to provide shielding of an electromagnetic field emanating from the corona electrode.

A particle sensor includes an aperture for receiving a gas flow with entrained particles, an electrostatic particle charging section, a parallel-plate particle precipitation section; and a sensor for detecting precipitated particles to produce a sensor signal. The sensor signal I.sub.sensor is related to an apparent particle number concentration of the particles in the gas flow entering the charging section by a calibration constant S.sub.1, such that I.sub.sensor=f(N.sub.app, S.sub.1), the calibration constant being dependent on a count mean diameter of the particles in the gas flow entering the charging section according to a first relationship. The particle sensor includes a pre-filter positioned upstream from the charging section, the pre-filter filtering a part of the particles from the gas flow entering the pre-filter, a fractional degree of particle filtering depending on the count mean particle diameter of the particles entering the pre-filter according to a second relationship.

A gas purifying apparatus, including: at least one cylindrical ground electrode configured to receive gas flowing therethrough; a discharge electrode disposed centrally within each of the at least one cylindrical ground electrode; and a power supply electrically connected to the discharge electrode and the at least one cylindrical ground electrode so as to produce an electric field and a corona discharge from the discharge electrode to a corresponding cylindrical ground electrode to generate ions and free electrons into the gas to ionise substances in the gas for gas purification, wherein the discharge electrode and the corresponding cylindrical ground electrode form at least one plasma chamber when power from the power supply is applied, and wherein the discharge electrode includes: at least one annular plate having an outer edge extending towards the corresponding cylindrical ground electrode.

The invention relates to a rack (21, 27, 28) for supporting electrostatic filter plates (22, 23) of an electrostatic filter (20). The rack (21, 27, 28) is an elongated member comprising a plurality of notches (11) on a longitudinal side of the rack (21, 27, 28) for supporting a plate (22, 23) arranged to a notch (11). The rack (21, 27, 28) further comprises a slot (26) for adhesive arranged to be used at least for attaching the plates (22, 23) to the rack (21, 27, 28). The slot (26) is arranged on the opposite side of the rack (21, 27, 28) than notches (11). There is also an opening (24) in the first group of plates (22) at that point where the plates (22) are aligned with the voltage supply rack (28) but which are not attached to that rack (28). The invention further relates to an electrostatic filter (20) comprising a plurality of racks.

A cleaning device for cleaning an air-ionizing part of an electrode. The device comprises a cleaning member arranged to be in physical contact with the air-ionizing part of the electrode, the air-ionizing part of electrode and the cleaning member being arranged to slide relative to each other. The cleaning device further comprises an actuator arranged to activate the relative motion between the air-ionizing part of the electrode and the cleaning member. There is also provided an ionization electrode comprising the air-ionizing part and the cleaning device, as well as a ultrafine particle sensor, an air ionizer or an electrostatic air cleaner comprising such an electrode.