Abstract: A Petri net that corresponds to the mathematical model is determined and the Petri net includes the domination relationships and mutual dependency relationships between individual alarms. The Petri net is analyzed to determine a set of construction rules. The construction rules define an approach to reduce the number of alarms presented to an operator or a computer program.

Abstract: A Petri net that corresponds to the mathematical model is determined and the Petri net includes the domination relationships and mutual dependency relationships between individual alarms. The Petri net is analyzed to determine a set of construction rules. The construction rules define an approach to reduce the number of alarms presented to an operator or a computer program.

Abstract: A chemical cartridge for protective respiratory mask comprising a separate active filter section and main filter section. The active filter section is formed of an absorbent medium impregnated with a reagent capable to capture and derive a target toxic pollutant having a chemically active fuction into an inert, non-volatile and non-toxic matter as air is inhaled. This active filter section is permeable to other types of pollutant. The main filter section includes activated carbon, or any other equivalent filtering material, and is positioned downstream the active filter section. In operation, the target pollutant is captured and derived into inert, non-volatile and non-toxic matter by the active filter section, while the other types of pollutants pass through this active filter section and are captured by the main filter section.

Abstract: The invention relates to an improved sampling device for selectively collecting gaseous and aerosol pollutants contained in polluted air, said device being of the type comprising a cartridge provided with an inlet, an outlet and filtering means, a vacuum pump and means for connecting said pump to the outlet of the cartridge to cause some pulluted air to be drawn through said filtering means, the improvement wherein said filtering means consists of three successive filters and wherein: the first filter is made with a material of such a porosity that it collects aersol pollutants but is permeable to gas; the second filter is positioned downstream of the first filter and consists of a porous substrate impregnated with an effective amount of a chemical compound that reacts with one or more specific harmful or toxic gaseous pollutants to produce therefrom derivatives, said second filter being of such a porosity as to be permeable to air but not to said derivatives; and the third filter is positioned downstream of