Isokinetic sampling apparatus

Claim 1

APPARATUS FOR THE ISOKINETIC SAMPLING OF GASEOUSE FLUID COMPRISING: (A) AN INLET NOZZLE IMMERSED IN A MEDIUM OF FLOWING GASEOUS FLUID TO BE SAMPLED; (B) MEANS FOR MAINTAINING THE POSITION OF SAID INLET NOZZLE WITH THE OPENING THEREOF FACING INTO THE DIRECTION OF FLOW OF SAID FLUID; (C) MEANS FOR RECEIVING SAID GASEOUS FLUID ENTERING SAID NOZZLE TO COLLECT THE PARTICULATE BORNE BY SAID FLUID; (D) PROPORTIONING MEANS FOR RECEIVING SAID GASEOUS FLUID FROM THE AFORESAID COLLECTION MEANS AND A GASEOUS FLUID FROM A SOURCE OTHER THAN SAID COLLECTION MEANS AND COMBINING SAID GASEOUS FLUIDS INTO A DISCHARGE; (E) MEANS OPERATING AT A CONSTANT RATE OF FLOW FOR RECEIVING THE DISCHARGE OF SAID PROPORTIONING MEANS AND PUMPIANG SAME TO SOME HIGHER PRESSURE; AND (F) MEANS TO CONTROL THE OPERATION OF SAID PROPORTIONING MEANS TO MAINTAIN THE VELOCITY OF GASEOUS FLUID ENTERING SAID INLET NOZZLE AT A MAGNITUDE EQUAL TO THAT OF GASEOUS FLUID IN SAID MEDIUM ADJACENT TO SAID NOZZLE; (G) SAID PROPORTIONING MEANS CONSISTING OF FIRST AND SECOND NOZZLES HAVING ADJUSTABLE THROAT AREAS AND MEANS EFFECTED BY SAID CONTROL MEANS FOR REGULATING THE THROAT AREA OF SAID NOZZLES TO PERMIT SELECTIVE CONTROL OVER FLUID FLOW RATES THROUGH SAID FIRST AND SECOND NOZZLES, THE TOTAL FLOW THROUGH SAID PROPORTIONING MEANS BEING SUBSTANTIALLY CONSTANT OVER THE RANGE OF OPERATION OF SAID APPARATUS; (H) SAID PUMP MEANS OPERATING AT A RATE OF FLOW INSURING SONIC FLUID VELOCITIES IN THE THROAT AREAS OF SAID NOZZLES.