Patent ID: 7908937

Claim:
A method for determining the quantity of a contaminant in a fluid flow system, comprising the steps of: (a) isolating a section of the flow system with at least two valves to form an isolated section, wherein the flow system is a pipe or duct that is at least partially filled with a gas, and the valves isolate the section of the pipe or duct from other sections of the pipe or duct; (b) injecting a gaseous conservative tracer and a gaseous interactive tracer into the isolated section of the flow system at a first location, wherein the interactive tracer is a partitioning tracer; (c) advecting the tracers along the isolated section of the flow system in gas phase with an advection gas; (d) extracting the tracers at a second location in the flow system; (e) measuring the concentration of the extracted tracers over a period of time; and (f) characterizing the contaminant from the concentrations of the tracers, wherein the quantity of extracted tracer is related to the quantity of contaminant.