Patent ID: 6938456

Claim:
A method of testing a vacuum detection device, the method comprising: providing a pressure source at a first pressure level; drawing with a vacuum generating device a vacuum at a second pressure level, the vacuum generating device including: a passage including a constriction defining an orifice; a first valve connecting the passage and an ambient environment, the first valve being electrically positionable in first and second configurations, the first configuration permitting generally unrestricted fluid flow between the orifice and the ambient environment, and the second configuration substantially preventing fluid flow between the orifice and the ambient environment; a second valve in fluid communication with the pressure source, the second valve being electronically adjustable; and a fluid communication conduit connecting the passage and the second valve, and the fluid communication conduit including a fluid communication tap at a second pressure level; wherein the drawing includes positioning the first valve to the second configuration such that a pressure in the fluid communication conduit and at the fluid communication tap changes at a first rate during a first portion of a test period; connecting the vacuum detection device to the fluid communication tap; sensing the second pressure level, the sensing including outputting a first electric signal commensurate with the second pressure level; processing the first electric signal, the processing including outputting a second electric signal based on the first electric signal; and varying fluid flow through the orifice, the varying including adjusting the second valve in response to the second electric signal.