Patent attributes
A test device and method for drawing a vacuum relative to an ambient environment. The device includes a member defining a passage, a valve, and a fluid communication conduit. The passage extends between a first end and a second end, and includes a constriction defining an orifice. The first end is in fluid communication with an ambient environment. The valve has a first port and a second port. The first port is adapted for fluid communication with a pressure source at a first pressure level. The fluid communication conduit includes a fluid communication tap at a second pressure level. The second pressure level is responsive to fluid flow through the orifice. The fluid communication conduit connects the second end of the member and the second port of the valve.