Patent ID: 6789433
Filing Date: 2004-09-14
Classification: G01F

Abstract:
A method for detecting a blockage in the outlet of a purged enclosure having an outlet monitoring device in said outlet, said outlet monitoring device having a sealed chamber with only one inlet, an outlet, only one path between said only one inlet and said outlet and a flow restrictor in said only one inlet and a flow restrictor in said outlet through which a purging fluid can flow, said method comprising:flowing said purging fluid into said enclosure; monitoring at a first differential pressure switch the difference in pressure between the pressure in said enclosure and said sealed chamber that results from said purging fluid flow through said first restrictor of said outlet device; monitoring at a second differential pressure switch the difference in pressure between said sealed chamber pressure and the pressure outside of said enclosure that results from said purging fluid flow through said second restrictor of said outlet device; and determining that either said first or second restrictors are blocked when said second or said first switches, respectively, are open when said purging fluid flows.