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:
May. 10, 2005
Filed:
Aug. 27, 2003
Warren Baxter Nicholson, El Paso, TX (US);
Louis L. Nagy, Warren, MI (US);
Warren Baxter Nicholson, El Paso, TX (US);
Louis L. Nagy, Warren, MI (US);
Delphi Technologies, Inc., Troy, MI (US);
Abstract
A method and apparatus for detecting the concentration of soot particles in engine oil. A microwave signal having a varying frequency is applied to a transmission line having a probe tip exposed to the engine oil. A voltage is read at a stationary detection point along the length of the transmission line for each applied frequency. The applied frequency when the probe voltage is equal to a null voltage of a standing wave within the transmission line is compared to a reference frequency determined when the probe voltage is equal to a null voltage for a known concentration of soot particles. The concentration is calculated based upon the result of the comparison. Preferably, a reference probe receives the same input signal. A known relationship between the reference probe and the transmission line is then used to eliminate temperature effects on the applied frequency.