Method and system for determining oil quality

• US 6,278,282 B1
• Filed: 10/07/1999
• Issued: 08/21/2001
• Est. Priority Date: 10/07/1999
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: Marszalek, Gary A.
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): Deb, Anjan K
• Application Number:
  US09/413,771
• Time in Patent Office: 684 Days
• Field of Search: 324/658, 324/663, 324/672, 324/698, 324/699, 324/709, 324/713, 324/683, 324/553, 340/603
• US Class Current: 324/663
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

A method for determining quality of lubricating oil using electrodes in contact with the oil includes applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current will flow; determining a first voltage phase lag with respect to the potential when the potential has the first amplitude; increasing amplitude of the potential to a second amplitude at which solution current flows; determining a second voltage phase lag with respect to the potential when the potential has the second amplitude; and determining the quality of the oil based on the voltage phase lags. A system for practicing the method is also provided.

Claims

1. A method for determining quality of lubricating oil using electrodes in contact with the oil, the method comprising:

applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

determining a first voltage phase lag with respect to the potential when the potential has the first amplitude;

increasing amplitude of the potential to a second amplitude at which solution current flows;

determining a second voltage phase lag with respect to the potential when the potential has the second amplitude; and

determining the quality of the oil based on the voltage phase lags.

2. The method of claim 1 wherein applying a first potential comprises applying a substantially symmetrically balanced time-varying potential.

3. A method for determining quality of lubricating oil, the method comprising:

applying a potential having a first amplitude to electrodes in contact with the oil, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

increasing amplitude of the potential to a second amplitude at which detectable solution current begins to flow; and

determining the quality of the oil based on the second amplitude.

4. The method of claim 3 wherein applying a potential comprises applying a substantially symmetrically balanced time-varying potential.

5. The method of claim 3 further comprising monitoring voltage phase lag with respect to the potential in order to determine when detectable solution current begins to flow.

6. A method for determining quality of lubricating oil, the method comprising:

positioning first and second electrodes in the oil;

applying a potential having a first amplitude to the electrodes, wherein the first amplitude is below a redox potential of the oil;

determining a first voltage phase lag with respect to the potential when the potential has the first amplitude;

increasing amplitude of the potential to a second amplitude above the redox potential;

determining a second voltage phase lag with respect to the potential when the potential has the second amplitude;

determining solution current based on the voltage phase lags; and

determining the quality of the oil based on the solution current.

7. A system for determining quality of lubricating oil, the system comprising:

first and second electrodes adapted to contact the oil; and

a microprocessor in communication with the electrodes, the microprocessor including instructions for applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

instructions for determining a first voltage phase lag with respect to the potential when the potential has the first amplitude;

instructions for increasing amplitude of the potential to a second amplitude at which solution current flows;

instructions for determining a second voltage phase lag with respect to the potential when the potential has the second amplitude; and

instructions for determining the quality of the oil based on the voltage phase lags.

8. A system for determining quality of lubricating oil, the system comprising:

first and second electrodes adapted to contact the oil; and

a microprocessor in communication with the electrodes, the microprocessor including instructions for applying a potential having a first amplitude to electrodes in contact with the oil, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

instructions for increasing amplitude of the potential to a second amplitude at which detectable solution current begins to flow; and

instructions for determining the quality of the oil based on the second amplitude.

9. A computer readable storage medium having information stored thereon representing instructions executable by a controller to determine quality of lubricating oil using electrodes in contact with the oil, the computer readable storage medium comprising:

instructions for applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

instructions for determining a first voltage phase lag with respect to the potential when the potential has the first amplitude;

instructions for increasing amplitude of the potential to a second amplitude at which solution current flows;

instructions for determining a second voltage phase lag with respect to the potential when the potential has the second amplitude; and

instructions for determining the quality of the oil based on the voltage phase lags.

10. A computer readable storage medium having information stored thereon representing instructions executable by a controller to determine quality of lubricating oil using electrodes in contact with the oil, the computer readable storage medium comprising:

instructions for applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current flows;

instructions for increasing amplitude of the potential to a second amplitude at which detectable solution current begins to flow; and

instructions for determining the quality of the oil based on the second amplitude.