Abstract: The invention relates to a method and an apparatus for measuring particle concentrations in an aerosol. The apparatus comprises means (103) for driving flow (105) into apparatus (101), means (115) for electrically charging particles (109) to become electrically charged particles (123) by ions (113) produced by a charger, means (117) for removing free ions (113) which are not attached to the electrically charged particles (123), and means (119) for measuring electrical current carried by the electrically charged particles (123). The means (115) for charging the particles and the means (119) for measuring electrical current carried by the electrically charged particles (123) are dimensioned such that the means (119) for measuring electrical current carried by the electrically charged particles (123) only measures a part of a total current carried by the particles.

Abstract: The invention relates to a method and an apparatus for measuring particle concentrations in an aerosol. The apparatus comprises means (103) for driving flow (105) into apparatus (101), means (115) for electrically charging particles (109) to become electrically charged particles (123) by ions (113) produced by a charger, means (117) for removing free ions (113) which are not attached to the electrically charged particles (123), and means (119) for measuring electrical current carried by the electrically charged particles (123). The means (115) for charging the particles and the means (119) for measuring electrical current carried by the electrically charged particles (123) are dimensioned such that the means (119) for measuring electrical current carried by the electrically charged particles (123) only measures a part of a total current carried by the particles.

Abstract: A boiler includes a flow channel having a selected chamber delimited by walls made at least partly of conductive material and being grounded, and a device arranged at least partially inside the selected chamber. The device includes an ion source comprising a corona electrode and an electrically passive body having an opening for corona discharge. The corona electrode is located inside the electrically passive body. A fan/shielding-gas connection is in the electrically passive body. The shielding gas exits the electrically passive body through the opening. The device also includes a high-voltage source for the corona electrode. The walls of the selected chamber of the boiler form a ground potential for the corona electrode to collect the fine particles of flue gases on the walls of the selected chamber.

Abstract: A gas cleaning apparatus includes: an ion source to provide an ion beam, a charging zone to form charged particles by exposing particles of a particle-laden gas to the ion beam, and a filter element to collect the charged particles, wherein the ion source includes a corona electrode to generate ions by a corona discharge, the ion source is arranged to form the corona discharge in a protective gas, and wherein the apparatus is arranged to form the ion beam by using an electric field to draw the generated ions from the corona discharge to the particle-laden gas.

Abstract: A method for collecting fine particles from flue gases onto selected collector surfaces includes leading the flue gases from a combustion chamber to a selected chamber that is part of a flow channel of the flue gasses. The selected channel is delimited by walls presenting the selected collector surfaces. Gas ions are formed with aid of a corona discharge of an ion source inside the selected chamber. The ion source includes a separate body relative to the selected chamber that is electrically passive and contains a corona electrode maintained at a high-voltage relative to the collector surfaces. The selected collector surfaces form a counter potential to the high voltage of the corona electrode. The gas ions are led to the selected chamber and mixed with the flue gases to charge the fine particles in the flue gas which are collected on the selected collector surfaces.

Abstract: A method for separating particles from particle-laden gas. Charged particles are formed by charging particles of a particle-laden gas. A gas jet is provided by guiding the particle-laden gas by a flow guide. Particles from the gas jet are collected to a collecting electrode by an electric field. An effective collecting area of the collecting electrode is positioned such that gas velocity gradient at each point of the effective collecting area is smaller than 10% of the maximum gas velocity in the gas jet divided by the height dimension of the jet.

Abstract: A process and an apparatus for coating glass by means of a method using at least one or more liquid raw materials which react essentially on at least a portion of the glass substrate forming a coating on it. At least part of the liquid raw materials is atomized to droplets with one or more two-fluid atomizer and at least a fraction of the gas used in the one or more two-fluid atomizers is electrically charged such that at least a fraction of the droplets become electrically charged during or after the atomization. According to the invention the droplets are formed into a separately created electric field.

Abstract: The invention relates to a method for detecting biological material in an airstream, in which method the airstream is fed with the aid of sampling devices, a light beam is emitted towards the airstream, a fluorescence signal depicting the fluorescence of the particle is created, a scattering signal depicting the scattering of the light of the particle is created, the fluorescence signal and the scattering signal are converted into discrete values, and an alarm value is defined. The discrete values are recorded cumulatively as hit points in an at least 2-dimensional measurement space equipped with selected dimensions, at least one index area is preselected from the measurement space, a cumulative index is calculated at an index frequency from the hit points accumulated on the each preselected index area, and an alarm value, showing the presence of a selected biological material, is defined from the indices by using a preselected criterion.

Abstract: The invention relates to a method for detecting biological material in an airstream, in which method the airstream is fed with the aid of sampling devices, a light beam is emitted towards the airstream, a fluorescence signal depicting the fluorescence of the particle is created, a scattering signal depicting the scattering of the light of the particle is created, the fluorescence signal and the scattering signal are converted into discrete values, and an alarm value is defined, the discrete values are recorded cumulatively as hit points in an at least 2-dimensional measurement space equipped with selected dimensions, at least one index area is preselected from the said measurement space, a cumulative index is calculated at an index frequency from the hit points accumulated on the each preselected index area, an alarm value, showing the presence of a selected biological material, is defined from the said indices by using a preselected criterion.

Abstract: A method for separating particles from particle-laden gas. Charged particles are formed by charging particles of a particle-laden gas. A gas jet is provided by guiding the particle-laden gas by a flow guide. Particles from the gas jet are collected to a collecting electrode by an electric field. An effective collecting area of the collecting electrode is positioned such that gas velocity gradient at each point of the effective collecting area is smaller than 10% of the maximum gas velocity in the gas jet divided by the height dimension of the jet.

Abstract: A process and an apparatus for coating glass by means of a method using at least one or more liquid raw materials which react essentially on at least a portion of the glass substrate forming a coating on it. At least part of the liquid raw materials is atomized to droplets with one or more two-fluid atomizer and at least a fraction of the gas used in the one or more two-fluid atomizers is electrically charged such that at least a fraction of the droplets become electrically charged during or after the atomization. According to the invention the droplets are formed into a separately created electric field.

Abstract: A method and a sensor device for determining particle emissions from exhaust gases of a combustion engine substantially during the use in an exhaust pipe system or a corresponding exhaust gas duct, in which method emitted particles contained in the exhaust gases are charged and the particle emissions are determined by measuring the electric charge carried by the emitted particles in the exhaust gas duct. The emitted particles are charged by varying the way of charging or the charging power with respect to time in such a manner that as a result of the charging, emitted particles brought into at least two different electrical charge states are present, wherein the charge of the emitted particles is further determined as a difference value/values measured from the emitted particles brought into said at least two different electrical charge states.

Abstract: The invention relates to a device (30) for determining the size distribution of aerosol particles from a flow (11), the device (30) comprising an electric mobility analyzer (10) and an impactor (20), connected to each other in such a way that the nozzle part (22a) of the first stage of the impactor (20) is simultaneously the bottom plate of said mobility analyzer (10).

Abstract: A method and a device for measuring density properies of a particle distribution, in which method a first parameter relating to the particle distribution is measured at a first measuring point (302), at least part of the flow that passed through the first measuring point is guided to the second measuring point (304), a second parameter relating to the particle distribution is measured at a second measuring point (305), and said first and second parameters relating to the particle distribution are used to determine at least one density property of the particle distribution of the original flow (306).

Abstract: A method and a sensor device for determining particle emissions from exhaust gases of a combustion engine substantially during the use in an exhaust pipe system or a corresponding exhaust gas duct, in which method emitted particles contained in the exhaust gases are charged and the particle emissions are determined by measuring the electric charge carried by the emitted particles in the exhaust gas duct. The emitted particles are charged by varying the way of charging or the charging power with respect to time in such a manner that as a result of the charging, emitted particles brought into at least two different electrical charge states are present, wherein the charge of the emitted particles is further determined as a difference value/values measured from the emitted particles brought into said at least two different electrical charge states.

Abstract: A method and a device for measuring properties of a particle distribution, in which a parameter relating to the mobility of the particles is measured at one measuring point (302) and a parameter relating to the aerodynamic size of the particles is measured at a second measuring point (305). By means of the measured parameters, at least one property of the particle distribution of the original flow is determined (306).

Abstract: A method and a device for measuring density properies of a particle distribution, in which method a first parameter relating to the particle distribution is measured at a first measuring point (302), at least part of the flow that passed through the first measuring point is guided to the second measuring point (304), a second parameter relating to the particle distribution is measured at a second measuring point (305), and said first and second parameters relating to the particle distribution are used to determine at least one density property of the particle distribution of the original flow (306).

Abstract: A method and a device for measuring properties of a particle distribution, in which a parameter relating to the mobility of the particles is measured at one measuring point (302) and a parameter relating to the aerodynamic size of the particles is measured at a second measuring point (305). By means of the measured parameters, at least one property of the particle distribution of the original flow is determined (306).

Abstract: The invention relates to a device (30) for determining the size distribution of aerosol particles from a flow (11), the device (30) comprising an electric mobility analyzer (10) and an impactor (20), connected to each other in such a way that the nozzle part (22a) of the first stage of the impactor (20) is simultaneously the bottom plate of said mobility analyzer (10).

Abstract: The subject of the invention is a method for minimizing Coulombic losses in impactors and an impactor, in which Coulombic losses have been minimized. The method according to the invention is based on restricting the force effect of the charges accumulated in impactor's insulators on the charged particles. This restriction of the force effect can be realized, for example, by placing an electrically conductive surface between the insulator and the flow, or by forming an insulator so that the force effect is minimized.