Sealed housing evaporative determination testing apparatus and method
First Claim
1. An apparatus operable for testing motor vehicle evaporative emissions comprising:
- a substantially air-tight testing structure operable for enclosing a subject motor vehicle, the testing structure containing a quantity of ambient air;
environmental control means for controlling temperature of the ambient air within the testing structure;
sampling means for withdrawing a portion of the ambient air from within the testing structure;
means for testing the sampled portion of the ambient air;
means for evacuating a portion of the ambient air contained within the testing structure and for filling a portion of air into the testing structure such that the pressure of the ambient air within the structure remains substantially constant;
means for testing the evacuated or filled air; and
means for determining the amount of evaporated emissions.
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Accused Products
Abstract
A computer controlled sealed housing evaporative determination (SHED) testing apparatus and method are provided for testing evaporative emissions for a motor vehicle. The SHED testing apparatus includes a substantially air-type testing structure for enclosing a subject motor vehicle and containing a quantity of ambient air. The ambient air is sampled at the beginning and end of a given test to measure the amount of hydrocarbons present therein. The apparatus undergoes a predefined testing procedure in which temperature of the air within the sealed testing structure is controlled in a predefined manner. To account for pressure changes due to the changing temperature, a portion of the ambient air contained within the testing structure may be evacuated from or introduced into the testing structure so as to maintain a substantially constant pressure differential of zero. The evacuated or introduced air is sampled and tested to determine the amount of hydrocarbons added into and evacuated from the testing structure. The total added and evacuated hydrocarbons are used with the beginning and end test measurements to determine a net evaporative emissions.
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Citations
16 Claims
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1. An apparatus operable for testing motor vehicle evaporative emissions comprising:
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a substantially air-tight testing structure operable for enclosing a subject motor vehicle, the testing structure containing a quantity of ambient air; environmental control means for controlling temperature of the ambient air within the testing structure; sampling means for withdrawing a portion of the ambient air from within the testing structure; means for testing the sampled portion of the ambient air; means for evacuating a portion of the ambient air contained within the testing structure and for filling a portion of air into the testing structure such that the pressure of the ambient air within the structure remains substantially constant; means for testing the evacuated or filled air; and means for determining the amount of evaporated emissions. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus operable for testing motor vehicle evaporative emissions comprising:
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a substantially air-tight testing structure operable for enclosing a subject motor vehicle, the testing structure containing a quantity of ambient air; environmental control means for controlling temperature of the ambient air within the testing structure so as to cycle the temperature through a variable temperature testing schedule; sampling means for withdrawing a portion of the ambient air from within the testing structure; a first hydrocarbon detector for testing the sampled portion of the ambient air both at a beginning and an end of a given test; an air flow element having an air passage for evacuating a portion of the ambient air contained within the testing structure and for filling a portion of air into the testing structure such that the pressure of the ambient air within the structure remains substantially constant; a second hydrocarbon detector for testing the evacuated or filled air to determine evaporative emissions added to and removed from the testing structure; and means for determining a net amount of evaporated emissions exhibited by a vehicle as a function of the beginning and end test and measured emissions added or removed during the test. - View Dependent Claims (9, 10, 11, 12)
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13. A method of testing evaporative emissions of a motor vehicle comprising:
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enclosing a subject motor vehicle in a substantially air-tight testing structure which has a substantially fixed volume and quantity of ambient air; sampling a portion of the ambient air from within the testing structure; controlling the temperature of the ambient air within the testing structure over a predefined testing cycle; evacuating a portion of the ambient air contained within the testing structure and filling a portion of air into the testing structure so that pressure of the ambient air within the testing structure remains substantially constant over a varying temperature range; determining the amount of hydrocarbons introduced into the ambient air and an amount of hydrocarbons released from the ambient air of the testing structure; and determining an amount of net evaporative emissions. - View Dependent Claims (14, 15, 16)
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Specification