Patent ID: 6830068
Filing Date: 2004-12-14
Classification: G01L,Y10T

Abstract:
A vacuum generating device comprising:a member defining a passage extending between a first end and a second end, the passage including a constriction defining an orifice; a first valve connecting the first end of the member and an ambient atmospheric environment, the first valve being adjustable between first and second configurations, the first configuration permitting generally unrestricted fluid flow between the orifice and the ambient atmospheric environment, and the second configuration substantially preventing fluid flow between the orifice and the ambient atmospheric environment; a second valve having a first port and a second port, the first part being adapted for fluid communication with a pressure source at a first pressure level; and a fluid communication conduit connecting the second end of the member and the second port of the second valve, and the fluid communication conduit including a fluid communication tap at a second pressure level, the second pressure level being responsive to fluid flow through the orifice; wherein the first and second valves are adjustable such that a pressure in the fluid communication conduit changes at a first rate during a first portion of a test period, and the pressure in the fluid communication conduit changes at a second rate during a second portion of the test period, and the test period is up to 10 seconds.