Process for determining rate of flow of gas through pipelines

Claim 1

A PROCESS FOR DETERMINING THE RATE OF FLOW OF GAS THROUGH A PIPELINE OR OTHER CONDUIT COMPRISING THE STEPS OF: FLOWING THE GAS THROUGH THE PIPELINE AT A RATE SUCH THAT THE REYNOLDS NUMBER EXCEEDS 1.5X10**4; INJECTING A SMALL AMOUNT OF TRACER MATERIAL INTO THE PIPELINE, SAID MATERIAL COMPRISING A DETECTABLE MATERIAL WHICH IS GASEOUS UNDER THE CONDITIONS EXISTING IN THE PIPELINE, IS INERT WITH RESPECT TO OTHER SUBSTANCES IN THE PIPELINE AND HAS A MOLECULAR WEIGHT OF AT LEAST TWICE THAT OF SAID GAS; DETECTING THE ARRIVAL OF THE INJECTED TRACER MATERIAL AT EACH OF TWO POINTS SPACED A KNOWN DISTANCE APART LONGITUDINALLY ALONG THE PIPELINE DOWNSTREAM OF THE POINT OF INJECTION OF THE TRACER MATERIAL; DETERMINING THE ACTUAL FLIGHT TIME OF THE INJECTED TRACER MATERIAL BETWEEN SAID TWO POINTS BY MEASURING THE ELAPSED TIME BETWEEN DETECTION OF ARRIVAL AT THE FIRST POINT AND THE DETECTION OF ARRIVAL AT THE SECOND POINT, MEASURING THE APPARENT FLIGHT TIME OF THE TRACER MATERIAL FROM ITS POINT OF INJECTION TO AT LEAST ONE OF SAID POINTS AND COMPARING SAID APPARENT FLIGHT TIME WITH SAID ACTUAL TIME, TAKING INTO ACCOUNT RESPECTIVE FLIGHT DISTANCES INVOLVED, TO OBTAIN AN ACTUAL FLIGHT TIME BETWEEN SAID POINT OF INJECTION AND AT LEAST ONE OF SAID TWO POINTS.