Abstract: The invention relates to a method for determining the particle size distribution of an aerosol by means of an aerosol measuring device and to an aerosol measuring device. Aerosol particles of the aerosol flowing through the measuring cell are illuminated in the measuring cell by a light beam. The scattered light is picked up by a detector, so that light signals of the aerosol particles can be detected spectroscopically in terms of intensity. From this, a size distribution of the light signals that is representative of a particle size distribution is produced. A known standard particle size distribution of dry aerosol particles is adapted to the measured particle size distribution, so that moisture influences are eliminated from the measured particle size distribution in this way.

Abstract: A device for characterizing particles of exhaled air. The device comprises an inlet line directed towards an outer environment with a filter for filtering particles. The inlet line is fluidly connected to a breathing line which comprises an interface through which air is breathable. A measurement line is fluidly connected to the breathing line and is fluidly connected to a particle measurement device for determining a parameter corresponding to the particles of the exhaled air. An inventive method comprises the following steps: Directing ex- haled air to a particle measurement device and determining a parameter corresponding to the particles of exhaled air, the parameter being at least one of the following parameters: Particle number, particle concentration (density), particle diameter, particle mass, particle size distribution, particle mass distribution, particle mass concentration, particle number concentration.

Abstract: A method for determining a source-dependent particle size distribution of an aerosol by an aerosol measuring device. First, a fraction parameter is determined that corresponds to a fraction of a source-dependent aerosol part of the aerosol. In addition, a particle size distribution of the aerosol particles is determined such that the source-dependent particle size distribution of the aerosol is determined from the fraction parameter and the particle size distribution. In terms of the device, the invention comprises an aerosol measuring device for determining a source-dependent particle size distribution of an aerosol, by means of which aerosol measuring device a fraction parameter can be determined that corresponds to a fraction of a source-dependent aerosol part of the aerosol. A particle size distribution of the aerosol particles can be determined such that the source-dependent particle size distribution of the aerosol can be determined from the fraction parameter and the particle size distribution.

Abstract: In order to achieve improved determination of fine dust particles, a method is provided for determining particles of an aerosol whereby, in a first measuring step, aerosol is fed to an optical aerosol measuring device without being influenced by a controllable centrifugal separator, at least in a further measuring step aerosol is guided to the optical measuring device while being influenced by the centrifugal separator rotating at least at a speed deviating from the speed 0, and properties of the particles of the aerosol are determined from the received measurement signals of the optical measuring device in the first and in at least one further measuring step. A device is also provided, which has an optical sensor unit forming the measuring volume for recording particles, and is designed such that a separator for size- and/or mass-sensitive separation of particles is arranged upstream of the sensor unit.

Abstract: A method for determining a particle velocity of an aerosol by means of an aerosol measuring device. Aerosol particles flow through a measuring cell and are illuminated with an electromagnetic beam. The scattered light is registered and detected by a sensor. The temporal signal durations of the scattered light signals are determined, and the particle velocity of the aerosol is determined on the basis of the signal durations. Furthermore, the invention provides an aerosol measuring device designed to carry out the steps of the method according to the invention for determining the particle velocity of an aerosol. In addition, a computer program having program code means is provided, which computer program is configured to carry out the steps of the method according to the invention.

Abstract: A process dilutes an aerosol by feeding an input aerosol through an inlet pipe surrounded by an annular space to a first mixing stage. An output aerosol leaves purified via an outlet as a particle-free clean gas. The particle-free clean gas is fed to the annular space upstream of the outlet and is mixed with the aerosol. A mixing stage includes an inlet pipe feeding aerosol as inlet aerosol. A downstream purification device purifies outlet aerosol leaving the mixing stage via an outlet pipe to form the particle-free clean gas. A mass flow controller and a pump suction off the outlet aerosol from the outlet pipe. A return line, for the clean gas, leads upstream into the annular space.

Abstract: A device for condensing vapor on condensation nuclei, especially for a particle counter, includes an inlet, via which a gas stream carrying particles as condensation nuclei enters into a feed channel; with a saturation channel. An evaporation unit extends over at least a part of the saturation channel. In the evaporation unit a working liquid can be evaporated in the saturation channel. An outlet leads to a measuring unit. At least one flow passage is provided from the feed channel towards the saturation channel. The at least one flow channel is directed at an angle greater than 90° in relation to a direction in which the feed channel extends.

Abstract: A method for detecting decalibration of a device for analyzing particles, including irradiating particles with light, detecting light scattered from the particles, amplifying, digitizing and detecting the electric signal obtained in a plurality of digital channels corresponding to the intensity representing the particle size and monitoring the appearance of the Mie peak in the measured size-dependent frequency distribution and sending a report if the Mie peak deviates in a digital channel other than the digital standard channel belonging to it based on measurement settings. The electronic analyzing unit detecting a Mie peak in the measured particle size distribution and assigning it to a digital detection channel in a device for detecting the concentration of small particles in gas, with a sample tube, a light source, a detector detecting scattered light scattered on the particles, an analog amplifier, an analog-digital converter, an electronic analyzing unit and a display and operating unit.

Abstract: For the reliable condensation of steam on condensation nuclei in an aerosol flow and therefore for enlarging the particles in the aerosol, the invention provides a method which is characterized in that condensation nuclei are passed through an inner area of an evaporating zone forming a flow area, the liquid to be evaporated is contacted with the flow area and evaporated therein and the thus produced steam is condensed on the condensation nuclei. the invention also provides an apparatus for condensing steam on condensation nuclei with an inlet for condensation nuclei and an evaporating zone constructed in such a way that a flow area for the condensation nuclei has a heated liquid duct open thereto and that a condensation flue is connected to the flow area. The invention also provides methods and apparatuses for counting particles, for producing monodisperse aerosols using the aforementioned method or the aforementioned apparatus.

Abstract: For the reliable condensation of steam on condensation nuclei in an aerosol flow and therefore for enlarging the particles in the aerosol, the invention provides a method which is characterized in that condensation nuclei are passed through an inner area of an evaporating zone forming a flow area, the liquid to be evaporated is contacted with the flow area and evaporated therein and the thus produced steam is condensed on the condensation nuclei. The invention also provides an apparatus for condensing steam on condensation nuclei with an inlet for condensation nuclei and an evaporating zone constructed in such a way that a flow area for the condensation nuclei has a heated liquid duct open thereto and that a condensation flue is connected to the flow area. The invention also provides methods and apparatuses for counting particles, for producing monodisperse aerosols using the aforementioned method or the aforementioned apparatus.

Abstract: For the reliable condensation of steam on condensation nuclei in an aerosol flow and therefore for enlarging the particles in the aerosol, the invention provides a method which is characterized in that condensation nuclei are passed through an inner area of an evaporating zone forming a flow area, the liquid to be evaporated is contacted with the flow area and evaporated therein and the thus produced steam is condensed on the condensation nuclei. the invention also provides an apparatus for condensing steam on condensation nuclei with an inlet for condensation nuclei and an evaporating zone constructed in such a way that a flow area for the condensation nuclei has a heated liquid duct open thereto and that a condensation flue is connected to the flow area. The invention also provides methods and apparatuses for counting particles, for producing monodisperse aerosols using the aforementioned method or the aforementioned apparatus.

Abstract: An apparatus for producing a solid aerosol, such as a carbon aerosol, in which aerosol particles are produced by spark discharge via particle-supplying electrodes and the particles are entrained by a gas flow. Electrodes having parallel, adjacent end faces and are prvided with a feed drive moving them synchronously in a direction toward one another.

Abstract: An apparatus for producing a solid aerosol from a heap, with a solids container, a feed piston, a rotary brush, an air intake and an outlet passage. To improve the constancy of the particle output the outlet passage has a non-increasing cross-section over a length thereof, with an increasing depth. In addition, in the outlet path of the solid aerosol it is possible to provide a light detector, which is connected by a regulating device to a drive of the piston.