Patent ID: 7331248

Claim:
A method for determining the location of a contaminant in an enclosed gaseous flow system within a structure, comprising the steps of: (a) injecting a gaseous conservative tracer and a gaseous partitioning tracer into the gaseous flow system at a first location; (b) advecting the tracers along the gaseous flow system at a first speed to create an advection flow field; (c) extracting the tracers at a second location in the gaseous flow system; (d) introducing a perturbation to the advection flow field at a perturbation time by changing and then re-establishing the advection flow at a second advection speed, which may be different than the first advection speed, creating a unique change in the concentration of the partitioning tracer; (e) extracting the partitioning tracer as a function of time relative to the perturbation time; (f) measuring the concentration of the partitioning tracer as a function of the time; and (g) determining the location of contamination from the time of arrival of the partitioning tracer relative to the perturbation time and the advection flow speed.