Diesel engine lubricating oil contaminant sensor method

• US 6,911,830 B2
• Filed: 08/22/2002
• Issued: 06/28/2005
• Est. Priority Date: 08/22/2002
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Wang, Su-Chee Simon, Heremans, Joseph Pierre, Schroeder, Thaddeus, Nagy, Louis L.
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): Nguyen, Vincent Q
• Application Number:
  US10/226,100
• Publication Number:
  US 20040036487A1
• Time in Patent Office: 1,041 Days
• Field of Search: 324/698, 324/658, 324/439, 324/441, 73/350.2, 73/530.1, 73/530.5, 73/530.6, 702/50
• US Class Current: 324/698
• CPC Class Codes: G01N 27/06 of a liquid involving electrolysis G01N27/26
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A method by which contaminant (soot) content in Diesel engine oil is determined using electrical conductivity measurements of the Diesel oil at a high frequency, or by which contaminant (soot and/or water and/or anitfreeze) content is determined using the ratio of electrical conductivity measurements of the Diesel oil at a high frequency to the electrical conductivity measurements of the Diesel oil at a low frequency. Both the conductivity ratio and the high frequency conductivity are essentially independent of the brand of oil. High frequency is defined to be above 2 MHz whereas low frequency is defined to be D.C. to about 1 kHz.

Claims

1. A method for determining engine lubricating oil condition of a Diesel engine, comprising the steps of:

measuring a selected one of conductivity and conductance of lubricating oil of a Diesel engine at a frequency above of about 2 MHz to thereby provide a first measured value;

measuring the selected one of conductivity and conductance of the oil at a frequency below about 1 KHz to thereby provide a second measured value;

measuring a temperature of the oil taken substantially contemporaneously with said second step of measuring;

determining a first oil condition constant, m;

determining a second oil condition constant, b;

wherein m and b are determined based upon a predetermined relationship with respect to the measured temperature;

calculating a ratio, Y, of the first measured value with respect to the second measured value;

calculating a contaminant concentration, X, based upon a relation;

Y=mX+b; and

determining whether X has reached a predetermined threshold;

wherein if X is below the threshold, then the engine oil condition has a first condition; and

if X is at least one of at the threshold or above the threshold, then the engine oil condition has a second condition.

2. The method of claim 1, further comprising generating an indication which is indicative of the engine oil having the second condition.

3. The method of claim 1, wherein said first measured value is measured at a selected frequency substantially between about 2 MHz and about 50 MHz.

4. The method of claim 3, further comprising generating an indication which is indicative of the engine oil having the second condition.

5. The method of claim 1, wherein said step of calculating calculates at least one of soot concentration of the oil, water concentration of the oil, and antifreeze concentration of the oil below about 2 percent by volume.

6. The method of claim 5, wherein said first measured value is measured at a selected frequency substantially between about 2 MHz and about 50 MHz.

7. The method of claim 6, further comprising generating an indication which is indicative of the engine oil having the second condition.

8. A method for determining engine lubricating oil condition of a Diesel engine, comprising the steps of:

measuring a selected one of conductivity and conductance of lubricating oil of a Diesel engine at a frequency above of about 2 MHz to thereby provide a first measured value;

measuring the selected one of conductivity and conductance of the oil at a frequency below about 1 KHz to thereby provide a second measured value;

measuring a temperature of the oil taken substantially contemporaneously with said second step of measuring;

determining a first oil condition constant, m;

determining a second oil condition constant, b;

wherein m and b are determined based upon a predetermined relationship with respect to the measured temperature;

calculating a ratio, Y, of the first measured value with respect to the second measured value;

calculating a soot concentration, X, based upon a relation;

Y=mX+b; and

determining whether X has reached a predetermined threshold;

wherein if X is below the threshold, then the engine oil condition has a first condition; and

if X is at least one of at the threshold or above the threshold, then the engine oil condition has a second condition.

9. The method of claim 8, further comprising generating an indication which is indicative of the engine oil having the second condition.

10. The method of claim 8, wherein said first measured value is measured at a selected frequency substantially between about 2 MHz and about 50 MHz.

11. The method of claim 10, further comprising generating an indication which is indicative of the engine oil having the second condition.

12. A method for determining engine lubricating oil condition of a Diesel engine, comprising the steps of:

measuring a selected one of conductivity and conductance of lubricating oil of a Diesel engine at a frequency above of about 2 MHz to thereby provide a measured value, Y;

determining a first oil condition constant, m;

determining a second oil condition constant, b;

calculating a soot concentration, X, based upon a relation;

Y=mX+b; and

determining whether X has reached a predetermined threshold;

wherein if X is below the threshold, then the engine oil condition has a first condition; and

if X is at least one of at the threshold or above the threshold, then the engine oil condition has a second condition.

13. The method of claim 12, further comprising generating an indication which is indicative of the engine oil having the second condition.

14. The method of claim 12, wherein said first measured value is measured at a selected frequency substantially between about 2 MHz and about 50 MHz.

15. The method of claim 14, further comprising generating an indication which is indicative of the engine oil having the second condition.