Abstract: An n-alkane with the general chemical formula CnH2n+2 with an ordinal number n of ten, eleven or twelve is used as operating medium (7) for a condensation nucleus counter for exhaust gases from internal combustion engines (4) by which individual particles contained in the exhaust gas can be counted.

Abstract: An n-alkane with the general chemical formula CnH2n+2 with an ordinal number n of ten, eleven or twelve is used as operating medium (7) for a condensation nucleus counter for exhaust gases from internal combustion engines (4) by which individual particles contained in the exhaust gas can be counted.

Abstract: For a method for determining the concentration of aerosols in hot gases, particularly in exhaust gases of internal combustion engines, the removal of volatile and semi-volatile particles by heating the exhaust gas is provided, as well as the measurement of the concentration of the aerosols, optionally in a partial flow of an optionally diluted exhaust gas flow. In order to enable precise measurements of the aerosol concentration in the exhaust gas with lower energy consumption, the exhaust gas is divided in a first stage into two partial flows, both of which are heated, with one of the partial flows being filtered at least once, preferably before heating, and the two partial flows are subsequently recombined. In a second stage, the exhaust gas is again divided into two partial flows, with one of the partial flows being heated even further than in the first stage, and with the other partial flow being filtered at least once.

Abstract: A condensation particle counter comprising a saturation unit (1) and a downstream condensation unit (2), through which at least one channel (5) for an aerosol flow passes between an inlet (3) and an outlet (4) that leads to a counting unit (16). The saturation unit (1) and the condensation unit (2) comprise a shell sleeve (12) having an inner shell wall (21) that is penetrated by a core (6), the core wall (20) and the inner shell wall (21) delimiting a channel (5) formed therebetween.

Abstract: For a method for determining the concentration of aerosols in hot gases, particularly in exhaust gases of internal combustion engines, the removal of volatile and semi-volatile particles by heating the exhaust gas is provided, as well as the measurement of the concentration of the aerosols, optionally in a partial flow of an optionally diluted exhaust gas flow. In order to enable precise measurements of the aerosol concentration in the exhaust gas with lower energy consumption, the exhaust gas is divided in a first stage into two partial flows, both of which are heated, with one of the partial flows being filtered at least once, preferably before heating, and the two partial flows are subsequently recombined. In a second stage, the exhaust gas is again divided into two partial flows, with one of the partial flows being heated even further than in the first stage, and with the other partial flow being filtered at least once.

Abstract: A method for detecting the number of particles in the exhaust gas of combustion engines, wherein a value that is characteristic for the quantity of the particles is determined, for example, in form of the blackening of a filter or determination of the concentration, wherein, furthermore, the suction time and/or the suction volume of the exhaust gas are measured, and wherein, if necessary, the blackening rate is calculated, based on the characteristic value and the suction time and/or the suction volume by way of a first conversion function, wherein the number of particles is determined based on the characteristic value, the suction time and/or the suction volume as well as the data of the first conversion function by way of a second conversion function.

Abstract: For a particularly compact device for removing the volatile particles from a sample gas with a simple design and a maximum of energy efficiency it is suggested to provide for a removal device (3) with an evaporator (7) and a catalyst (8), with the catalyst (8) being installed downstream of the evaporator (7), and furthermore to adjust the standard volumetric flow rate ({dot over (V)}) of the undiluted sample gas to a given catalytic efficiency of catalyst (8) by means of a flow limiting device (5).

Abstract: A device for determination of solid particle concentration includes a primary diluter (6), a downstream heated evaporator (7), a secondary diluter (8) downstream of the evaporator (7) and a particle counter (5). The secondary diluter (8) is a porous tube diluter and is mounted between the outlet of the evaporator (7) and a stabilization chamber (14), from which the sample flow is diverted to the particle counter (5).

Abstract: A rotating disc diluter (1) has a rotatable rotary element (4) which carries surface-accessible transfer volumes (9, 10) which along their common path of movement alternately glide over feed and discharge ports (11-18) for an undiluted fluid flow on the one hand and for a dilution fluid flow on the other hand. For the simple widening of the usable dilution rate range, the rotary element (4) has at least two rows of transfer volumes (9, 10) on different paths of movement, the associated feed ports (11-14) of which for the undiluted fluid flow and/or for the dilution fluid flow can be separately controlled.

Abstract: A reservoir (4) for the working fluid of the saturation unit (3) is connected with a sampling section (1) by a pressure equalization line (9) of the gas that is loaded with solid particles, as a result of which a sucking back of the working fluid from the reservoir (4) into the sampling section (1) and other sections of the measurement environment that are connected with such are prevented, even in the presence of unfavorable pressure conditions.

Abstract: A device for the dilution of a gas to be analyzed with a dilution gas has a sample gas tube (1) and a feed (3) for the dilution gas, which open into a common line (6) for the diluted gas to be analyzed. In order that even with large pulsatile pressures in the gas to be analyzed at the sample point no return flow of dilution air into the line of the gas to be analyzed and no uncontrolled temperature change of this gas can occur, the feed (3) for the dilution gas in the form similar to a Venturi jet (7) merges into the common line (6), the sample gas tube (1) is embodied so as to be thermally insulated with respect to the ambient air and dilution air and opens into the Venturi jet (7) just before the location with the smallest cross section.

Abstract: A reservoir (4) for the working fluid of the saturation unit (3) is connected with a sampling section (1) by a pressure equalization line (9) of the gas that is loaded with solid particles, as a result of which a sucking back of the working fluid from the reservoir (4) into the sampling section (1) and other sections of the measurement environment that are connected with such are prevented, even in the presence of unfavorable pressure conditions.

Abstract: A device for determination of solid particle concentration includes a pre-diluter (6), a downstream heated evaporator (7), a secondary diluter (8) downstream of the evaporator (7) and a particle counter (5) connected to such. The secondary diluter (8) is a porous tube diluter and mounted between the outlet of the evaporator (7) and a stabilization chamber (14), from which the sample flow is branched off for the particle counter (5). With it, the concentration of the solid particles can be measured easily and controllably within a wide range without any corruption as a result of volatile aerosol particles.

Abstract: Abstract A rotating disc diluter (1) has a rotatable rotary element (4) which carries surface-accessible transfer volumes (9, 10) which along their common path of movement alternately glide over feed and discharge ports (11-18) for an undiluted fluid flow on the one hand and for a dilution fluid flow on the other hand. For the simple widening of the usable dilution rate range, the rotary element (4) has at least two rows of transfer volumes (9, 10) on different paths of movement, the associated feed ports (11-14) of which for the undiluted fluid flow and/or for the dilution fluid flow can be separately controlled.