Abstract: A system for air decontamination in a three-dimensional space described herein includes an air inlet for drawing in air, an air outlet for administering filtered air, and a filter device for filtering air prior to administration through the air outlet, the system is configured to draw air in a substantially vertical laminar flow from a ground of the space to the air inlet. A filter device for filtering ultrafine particles from a gas described herein includes a first filter medium for absorbing polar liquids but not ultrafine particles; in fluid communication with a second filter medium for absorbing ultrafine particles; and a gas outlet, the first filter medium is configured to allow vaporization of the absorbed polar liquids; the device is configured to guide the gas from the first to the second filter medium and through the second filter medium; and the second filter medium forms the gas outlet.

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 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: According to the invention, particles of an aerosol are firstly charged in a unipolar manner in a diffusion charger (10). They are subsequently led through a diffusional precipitator (20) in which a part of the particles is precipitated. The diffusional precipitator current is measured and a value for the number concentration is evaluated from the current. A single diffusional precipitator may be used for this. According to preferred embodiment, a means for measuring the influence current and/or an aerosol electrometer are additionally present, by way of which one may measure a complete current. The latter additionally permits the evaluation of the average particle size. Additionally, one may determine an elementary carbon total quantity from the average particle size with the help of a measurement of the photoelectric charging carried out in parallel.

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: 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: According to the invention, particles of an aerosol are firstly charged in a unipolar manner in a diffusion charger (10). They are subsequently led through a diffusional precipitator (20) in which a part of the particles is precipitated. The diffusional precipitator current is measured and a value for the number concentration is evaluated from the current. A single diffusional precipitator may be used for this. According to preferred embodiment, a means for measuring the influence current and/or an aerosol electrometer are additionally present, by way of which one may measure a complete current. The latter additionally permits the evaluation of the average particle size. Additionally, one may determine an elementary carbon total quantity from the average particle size with the help of a measurement of the photoelectric charging carried out in parallel.

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.

Abstract: A supply circuit for a fluorescent tube installation with a high-voltage transformer (T) which is connected, input-end, to a supply voltage with a frequency of several hundred Hz, and which is formed without an air gap. To replace the air gap in the transformer, an electronic regulator (EST) is nonetheless used in the supply circuit, which emulates the current-limiting function of an air gap. The frequency of the supply voltage is between 300 and 800 Hz, preferably 400 Hz. As these frequencies are higher than the usual network frequency of 50/60 Hz, the size and weight of the transformer can be considerably reduced.

Abstract: A method and a system for analyzing gas samples employ at least two semiconductor sensor sets, used alternately. The sensor output signals are time-differentiated. As a result of these features, the time required for analysis can be reduced considerably, especially with an uninterrupted sequence of analyses to be performed in succession.

Abstract: In order to increase the reliability of detection of gaseous contamination in containers, gas (G) from the container is subject to several different methods of analysis (54a to 54d), each of which emits differing output signal courses (I.sub.1 to I.sub.4), depending on the contaminants and their concentration. A vector of the state vector type (P.sub.GAS) is formed with the output signals (I.sub.1 to I.sub.4) as a state variable and checked to see whether it defines a permissible or an unacceptable state of contamination (56). On the basis of this examination the decision is taken whether a container is acceptably or unacceptably contamined.

Abstract: In a combustion process a fuel is mixed with an oxygen-containing gas in an adjustable ratio. This fuel-gas-mixture is burned and thereby an exhaust gas is produced. At least a part of the exhaust gas is collected and exposed to an ultra violet radiation source, thereby generating positive and negative charge carriers in the exhaust gas by means of a photoelectric charge separation process. The kind or amount of the positive and/or negative charge carriers is detected to produce a measurement value which reflects the amount and/or the charge of the carriers. Therefrom a control signal is derived and the mixture-ratio of the oxygen-containing gas and the fuel, the so-called .lambda.-factor, is adjusted in response to said control signal in order to improve the efficiency of the combustion and to reduce the emission of toxic substances.

Abstract: Aerosol particles, resulting from the combustion of organic substances with insufficient oxygen supply, usually contain toxic, higher hydrocarbonic substances (e.g. tar) on their surface. These substances, e.g. tar, has the property to be photoelectrically more active than other substances contained in the atmosphere. In the method and apparatus according to the invention an aerosol, i.e. the carrier gas containing the particles to be characterized, is used which has been brought to at least one predetermined temperature sufficient for evaporation or decomposition or preventing condensation of molecules on particles of said aerosol that quench or enhance photoelectric activity. Such aerosol is exposed to electromagnetic radiation and, thereby, activated to electron emission. Thereafter the charge of the photoelectrically positively charged particles is determined by means of size selective filter means which are connected to current or charge measuring equipment.

Abstract: The invention relates to a fire detector having a measuring chamber defined by two electrodes, so that a non-ionizing electric field is produced between the electrodes by a DC voltage source. The measuring electrode is connected to the input of a current measuring device without direct connection with the DC voltage source. As soon as charged particles of smoke penetrate into the measuring chamber between the electrodes, the electric field causes the positive and negative particles to drift. The charge drift induces a current into the measuring electrode which is measured.