Abstract: A method for delivering at least two working gases from a common air supply comprising the steps of depleting the air in O2 in order to obtain a first gas mixture having an O2 content less than or equal to t1; delivering at least a portion of this first gas mixture as a first working gas; depleting another portion of this first gas mixture in O2 in order to obtain the second gas mixture having an O2 content less than or equal to t2, wherein t1 is greater than t2; and delivering the second gas mixture as a second working gas.

Abstract: A method for dry fluxing at least one metallic surface of an article comprising the steps of:a) passing at least one initial gas mixture comprising (1) at least one of an inert gas and a reducing gas and (2) an oxidizing gas mixture comprising water vapor into at least one apparatus for forming excited or unstable gas species, the initial gas mixture including 50 ppm to 6% water vapor;b) converting the at least one initial gas mixture to at least one primary gas mixture comprising excited or unstable gas species; andc) treating the surface to be fluxed, at a pressure close to atmospheric pressure, with a gaseous treatment atmosphere comprising excited or unstable gas species and substantially free of electrically charged species obtained from the primary gas mixture.

Abstract: Method of regulating the level of a given element in an atmosphere of an enclosure to a value below a predetermined upper limit (L.sub.h), comprising the steps of:a) providing at least a first gas source and a second gas source, the level of said element in the first source being greater than the level of the element in the second source;b) under nominal conditions, using the first gas source to supply the enclosure with a nominal flow rate Q.sub.n ;c) measuring the level of the element in the atmosphere of the enclosure at at least one point in the enclosure to obtain a measurement;d) if the result of the measurement taken during step c) is greater than a first predetermined upper threshold (L.sub.h -.epsilon.), cutting the supply to the enclosure from the first gas source and supplying the enclosure from the second gas source at a flow rate equal to, or substantially equal to, Q.sub.