Patent ID: 7043963
Filing Date: 2006-05-16
Classification: G01M,G01N

Abstract:
1. A system for testing motor vehicle evaporative emissions comprising: a substantially air-tight testing structure adapted for enclosing a motor vehicle to be placed under test, the testing structure containing a known volume of ambient interior air; a sampling mechanism for periodically measuring and analyzing total hydrocarbon content and component parts of the total hydrocarbon content in a sample of the ambient interior air; a pressure measuring mechanism for indicating a pressure differential between the ambient interior air and atmosphere outside of the testing structure; an injector element for injecting air containing substantially zero hydrocarbons into the testing structure whenever the pressure of the atmosphere outside of the testing structure is higher than the pressure of the ambient interior air by a preselected differential; an exhaling element for withdrawing interior ambient air from the testing structure whenever the pressure of the ambient interior air is higher than the pressure of the atmosphere outside of the testing structure by a redetermined differential; a flow measuring and calculation element for determining, in conjunction with a most recent sample from the sampling mechanism, an amount of hydrocarbons exhaled from the testing structure whenever the exhaling element is withdrawing interior ambient air from the testing structure; and a hydrocarbon source coupled to an interior of the testing structure via a gravimetric injection device.