Oil sensor systems and methods of qualitatively determining oil type and condition

• US 5,274,335 A
• Filed: 04/06/1992
• Issued: 12/28/1993
• Est. Priority Date: 04/06/1992
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Lee, Han-Sheng, Staley, David R., Wang, Su-Chee S., McGrath, Phillip B.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): Regan, Maura K.
• Application Number:
  US07/863,907
• Time in Patent Office: 631 Days
• Field of Search: 324/663, 324/664, 324/689, 324/690, 73/61.41, 73/61.43, 73/61.44
• US Class Current: 324/689
• CPC Class Codes: G01N 27/48 using polarography, i.e. measuring changes in current under a slowly-varying voltage
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

Disclosed is an oil sensor system having an oil sensor including two spaced apart electrodes, a triangular waveform means, a comparison means and a signal means. The oil system is used in situ (i.e., used directly in the engine) to determine the presence of two-stroke or four-stroke oil, or the occurrence of an engine malfunction, such as a leakage of antifreeze into the oil.

Claims

1. A method of determining the quality of an oil comprising:

placing two spaced apart electrodes in an oil to be tested;

applying an alternating current triangular waveform potential to the electrodes;

measuring the electrochemical current, being the induced current minus the capacitance component current, between electrodes; and

comparing the measured electrochemical current with predetermined values corresponding to two-stroke oil, four-stroke oil and oil including antifreeze.

7. A method as set forth in claim 1 wherein the applied potential as a constant rate.

8. A method as set forth in claim 1 wherein said potential has a maximum of 5V and a minimum of -5V.

9. A method as set forth in claim 8 wherein said constant rate is about 400V/sec.

2. An oil sensor system comprising:

two spaced apart electrodes;

a means for applying a triangular waveform potential to said electrodes;

a measuring means for measuring the electrochemical current, being the induced current minus the capacitance component current, between said electrodes;

a comparison means for comparing the measured electrochemical current with predetermined values corresponding to two-stroke oil, four-stroke oil and oil including antifreeze; and

a signal means for sending a display signal in a manner determined as a function of the comparison.

3. An oil sensor system as set forth in claim 2 wherein said means for applying an alternating current potential applies a maximum of 5V and a minimum of -5V.

4. An oil sensor system as set forth in claim 3 wherein the predetermined value corresponding to two-stroke oil is less than 0.4V at 50°

C.

5. An oil sensor system as set forth in claim 3 wherein the predetermined value corresponding to four-stroke oil range from about 1.8 to about 3.4V at 50°

C.

6. An oil sensor system as set forth in claim 3 wherein the predetermined value corresponding to oil including antifreeze is greater than 2V at 23°

C.

10. A device comprising:

an engine;

an oil reservoir;

two spaced apart electrodes positioned to contact oil used in the engine;

a means for applying a triangular waveform potential to the electrodes;

a measuring means for measuring the electrochemical current, being the induced current minus the capacitance component current, between the electrodes;

a comparison means for comparing the measured electrochemical current with predetermined values corresponding to two-stroke oil and four-stroke oil; and

a signal means for sending a signal as a function of the comparison.

11. A device as set forth in claim 10 wherein the predetermined value corresponding to the two-stroke oil is less than 0.4V at 50°

C., and the predetermined value corresponding to four-stroke oil ranges from about 1.8V to about 3.4V at 50°

C.

12. A device as set forth in claim 10 wherein the engine is a two-stroke engine.

13. A device as set forth in claim 12 wherein the electrodes are positioned in an oil reservoir to contact two-stroke combustion oil in the reservoir.

14. A device as set forth in claim 11 wherein the engine is a four-stroke engine.