Abstract: Volatile suspended particles are eliminated from an aerosol by heating the aerosol to a temperature at which the volatile suspended particles evaporate and diluting the aerosol with a dilution gas. The sequence heating and diluting may be performed in any order. According to another aspect of the invention, dilution of the raw gas takes place such that raw gas is led to a measurement gas channel through which measurement gas flows, wherein the quantity of raw gas transferred per unit of time is dependent on the volume flow in the raw gas channel. According to a further aspect of the invention, in a condensation nucleus counter the number and intensity of scattered light pulses evaluated in order to be able to draw conclusions on the reliability of the measurement.

Abstract: A device for filtering nanoparticulate matter below 300 nm in size from ambient air within a defined enclosed space comprises at least one filter medium containing at least one filter material, and a fan or blower, which blows or draws the air through the filter medium does so with sufficiently low air velocity in the filter medium that the air has a long residence time in the filter medium, during which time adhesive encounters between nanoparticulate matter and the solid phase of the filter material are highly probable. This air velocity is also being sufficiently low to ensure that, once adhesion has taken place, kinetic de-adhesion by the air flow is highly improbable. Such a device allows to keep the nanoparticle count inside the enclosed space kept below 5000/cc, equivalent to ‘natural woodland’, even though external levels may exceeded 200,000/cc: the removal of nanoparticles by cleaning making this <2.5% the external count.

Abstract: Volatile suspended particles are eliminated from an aerosol by heating the aerosol to a temperature at which the volatile suspended particles evaporate and diluting the aerosol with a dilution gas. The sequence heating and diluting may be performed in any order. According to another aspect of the invention, dilution of the raw gas takes place such that raw gas is led to a measurement gas channel through which measurement gas flows, wherein the quantity of raw gas transferred per unit of time is dependent on the volume flow in the raw gas channel. According to a further aspect of the invention, in a condensation nucleus counter the number and intensity of scattered light pulses is evaluated in order to be able to draw conclusions on the reliability of the measurement.

Abstract: The invention relates to the characterising, separating and/or elimination of suspended particles in a carrier gas of an aerosol. According to a first aspect of the invention volatile suspended particles are eliminated in that in a first step the aerosol is heated to a temperature at which the volatile suspended particles evaporate and in a second step the aerosol is diluted with a dilution gas. The sequence of the first and of the second step may be exchanged. According to a second aspect a dilution of the raw gas takes place such that raw gas is led to a measurement gas channel through which measurement gas flows, wherein the quantity of raw gas transferred per unit of time is dependent on the volume flow in the raw gas channel. According to a third aspect of the invention, in a condensation nucleus counter not only is the number of scatter light pulses evaluated but also their intensity in order to be able to draw conclusions on the reliability of the measurement.