The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 2009
Filed:
Mar. 22, 2006
Gerald Marek, Ann Arbor, MI (US);
Shahin Sabokdast Nudehi, East Lansing, MI (US);
Gerald Marek, Ann Arbor, MI (US);
Shahin Sabokdast Nudehi, East Lansing, MI (US);
AVL North America Inc., Plymouth, MI (US);
Abstract
A particulate sampler system includes a diluted exhaust mass flow controller that receives flow from a dilution mass flow controller and a laminar flow element (LFE). The dilution mass flow controller and LFE are fluidly arranged parallel to one another. A controller communicates with the mass flow controllers and the LFE to determine the flow through these devices, command valves in the mass flow controllers and generate data for determining calibration coefficients and correction factors. The diluted exhaust mass flow controller is calibrated and calibration coefficients are generated using a first to fourth order curve fit. Similarly, initial calibration coefficients are generated for the dilution mass flow controller. The diluted exhaust mass flow controller is set at a desired flow point. The dilution mass flow controller is varied between set points corresponding to different dilution ratios at the common, desired set point. The data obtained is used to determine a correction factor for example, by performing a linear curve fit of the data. The correction factor is applied to the calibration coefficients associated with the mass flow controllers.