Sensor device for monitoring the condition of a fluid and a method of using the same

• US 7,043,967 B2
• Filed: 09/30/2002
• Issued: 05/16/2006
• Est. Priority Date: 09/30/2002
• Status: Expired due to Term

• Current Assignee: University of Dayton
• Original Assignee: University of Dayton
• Inventors: Kauffman, Robert E., Wolf, James D.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Saint-Surin, Jacques M.
• Application Number:
  US10/260,754
• Publication Number:
  US 20040060344A1
• Time in Patent Office: 1,324 Days
• Field of Search: 73/531, 732/95, 732/92, 73/530.1, 73/530.4
• US Class Current: 73/53.01
• CPC Class Codes: G01N 33/28 Oils , i.e. hydrocarbon liquidsgaseous fuels G01N33/225; edible oils or edible fats G01N33/03
• CPC Class Codes: G01N 33/2835 specific substances contained in the oil or fuel
• CPC Class Codes: G01N 33/2847 Water in oil basic sediment and water G01N33/2823; oil in water G01N33/1833
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

The present invention is a compact apparatus and method that provides an efficient manner for monitoring the condition and level of a functional fluid directly in operating equipment. A sensor device is provided that includes a plurality of liquid sensors and a plurality of vapor sensors that when used in conjunction with one another at different temperatures, can provide a thorough evaluation of the oxidative degradation, liquid contamination and solid contamination of the fluid to detect the end of the useful life of the fluid. By providing liquid sensors and vapor sensors on the same device, the present invention allows for a compact, efficient, and economically feasible manner to monitor the condition of fluid as well as detecting abnormal operating conditions prior to further component damage and eventual equipment failure.

Claims

1. A sensor device for monitoring the condition of a fluid comprising:

a member;

a plurality of liquid sensors provided at various lengths along said member and each comprising at least two wires or wire rods for measuring liquid parameters of the fluid, said at least two wires or wire rods are adapted to be electrically connected to one another by the fluid when said at least two wires or wire rods are immersed in and in contact with the fluid to complete an electrical circuit such that in use current passes between said at least two wires or wire rods through the fluid in order to monitor the condition of the fluid; and

a plurality of vapor sensors in contact with vapors of the fluid for measuring vapor parameters of the fluid coupled to said member, at least one of said plurality of vapor sensors comprising conductive surfaces adapted to be electrically connected to one another by vapor of the fluid such that in use current passes between said conductive surfaces through the vapor, wherein said plurality of liquid sensors and plurality of vapor sensors are positioned a distance from one another so that said plurality of vapor sensors do not contact a liquid of the fluid.

2. A sensor device as claimed in claim 1, wherein said member is a dipstick.

3. A sensor device as claimed in claim 1, wherein said plurality of liquid sensors and said plurality of vapor sensors are adapted to operate simultaneously.

4. A sensor device as claimed in claim 1, wherein said plurality of liquid sensors further comprises at least one sensor array.

5. A sensor device as claimed in claim 4, wherein said at least one sensor array comprises sensors that are spaced between about 0.001 mm to about 1 mm apart.

6. A sensor device as claimed in claim 1, wherein said at least two wires or wire rods are spaced between about 0.1 mm and about 100 mm apart.

7. A sensor device as claimed in claim 1, wherein said plurality of vapor sensors comprises at least two conductive line surfaces provided on a nonconductive substrate.

8. A sensor device as claimed in claim 7, wherein said at least two conductive lines are spaced between about 0.1 mm and about 50 mm apart.

9. A sensor device as claimed in claim 1, wherein said plurality of vapor sensors comprises sensor arrays that are spaced between about 0.001 mm to about 1 mm apart.

10. A sensor device as claimed in claim 1, wherein said plurality of liquid sensors are formed from a conductive material selected from the group consisting of glassy carbon, platinum, gold, copper, copper alloys, nickel alloys, stainless steel, and combinations thereof.

11. A sensor device as claimed in claim 1, wherein said plurality of vapor sensors are formed from a conductive material selected from the group consisting of glassy carbon, platinum, gold) copper, copper alloys, nickel alloys, stainless steel, and combinations thereof.

12. A sensor device as claimed in claim 1, wherein said sensor device is adapted to measure fluid level, viscosity, temperature, electrical conductivity, electrochemical activity, water contamination, wear metals, soot buildup, coolant contamination, capacitance, dielectric constant, and combinations thereof.

13. A sensor device as claimed in claim 1, wherein said member is coupled to a fluid is selected from the group consisting of lubricating oils, transmission fluids, hydraulic fluids, transformer oils, metal working fluids, cooking oils, and combinations thereof.

14. A sensor device as claimed in claim 1, wherein said sensor device further comprises a magnet positioned behind one of said plurality of liquid sensors, said sensor device is adapted to measure a difference between outputs of said one of the liquid sensors having said magnet and remaining ones of said plurality of liquid sensors without said magnet, said difference being indicative of equipment wear detected by the sensor device.

15. A sensor device as claimed in claim 14, wherein said magnet is a magnetized line of a material which retains its magnetism to temperatures above about 700°

F.(371°

C.).

16. A sensor device as claimed in claim 1, wherein said sensor device further comprises an electronic system coupled to said member, said electronic system comprises electronics for said plurality of liquid sensors and said plurality of vapor sensors, and a readout display.

17. A sensor device as claimed in claim 1, wherein said plurality of vapor sensors comprises at least two wires or wire rods.

18. A sensor device as claimed in claim 17, wherein said at least two wires or wire rods are spaced between about 0.1 mm and about 50 mm apart.

19. A sensor device for monitoring the condition of a fluid comprising:

a member;

a plurality of liquid sensors for measuring liquid parameters of the fluid coupled to said member, said plurality of liquid sensors comprise at least one sensor array having conductive surfaces, said conductive surfaces adapted to be electrically connected to one another by the fluid when said conductive surfaces are immersed in and in contact with the fluid to complete an electrical circuit such that in use current passes between said conductive surfaces of said at least one sensor array through the fluid in order to monitor the condition of the fluid; and

a plurality of vapor sensors in contact with vapors of the fluid for measuring vapor parameters of the fluid coupled to said member, each of said plurality of vapor sensors comprising at least two wires or wire rods adapted to be electrically connected to one another by vapor of the fluid such that in use current passes between said at least two wires or wire rods through the vapor, wherein said plurality of liquid sensors and plurality of vapor sensors are positioned a distance from one another so that said plurality of vapor sensors do not contact a liquid of the fluid.

20. A sensor device as claimed in claim 19, further comprising an electronic system coupled to said member, said electronic system comprises electronics for said plurality of liquid sensors and said plurality of vapor sensors, and a readout display.

21. A sensor device as claimed in claim 19, wherein said conductive surfaces of said at least one sensor array are spaced between about 0.001 mm to about 1 mm apart.

22. A sensor device as claimed in claim 19, wherein said plurality of liquid sensors further comprises at least one wire or wire rod.

23. A sensor device as claimed in claim 19, wherein said plurality of vapor sensors comprises at least two wires or wire rods.

24. A sensor device as claimed in claim 19, wherein said plurality of vapor sensors further comprises at least one sensor array.

25. A sensor device as claimed in claim 24, wherein said at least one sensor array comprises conductive surfaces that are spaced between about 0.001 mm to about 1 mm apart.

26. A sensor device for monitoring the condition of a fluid comprising:

a member;

a plurality of liquid sensors having conductive surfaces for measuring liquid parameters of the fluid coupled to said member, said conductive surfaces adapted to be electrically connected to one another by the fluid when said conductive surfaces are immersed in and in contact wit the fluid to complete an electrical circuit such that in use current passes between said conductive surfaces through the fluid in order to monitor the condition of the fluid; and

a plurality of vapor sensors comprising at least one sensor array in direct contact with vapors of the fluid for measuring vapor parameters of the fluid coupled to said member, at least one of said plurality of vapor sensors comprising conductive surfaces adapted to be electrically connected to one another by vapor of the fluid such that in use current passes between said conductive surfaces through the vapor, wherein said plurality of liquid sensors and plurality of vapor sensors are positioned a distance from one another so that said plurality of vapor sensors do not contact a liquid of the fluid.

27. A sensor device as claimed in claim 26, wherein said at least one sensor array comprises sensors that are spaced between about 0.001 mm to about 1 mm apart.

28. A sensor device for monitoring the condition of a fluid comprising:

a member;

a plurality of liquid sensors having conductive surfaces for measuring liquid parameters of the fluid coupled to said member, said conductive surfaces of each liquid sensor adapted to be electrically connected to one another by the fluid when said conductive surfaces are immersed in and in contact with the fluid to complete an electrical circuit such that current may pass between said conductive surfaces through the fluid in order to monitor the condition of the fluid;

a plurality of vapor sensors in direct contact with vapors of the fluid for measuring vapor parameters of the fluid coupled to said member, each of said plurality of vapor sensors comprising at least two conductive surfaces adapted to be electrically connected to one another by vapor of the fluid such that in use current passes between said at least two conductive surfaces trough the vapor, wherein said plurality of liquid sensors and plurality of vapor sensors are positioned a distance from one another so that said plurality of vapor sensors do not contact a liquid of the fluid; and

a display system.

29. A method for monitoring the condition of a fluid comprising:

providing a sensor device having a plurality of liquid sensors and a plurality of vapor sensors on a member, each of said plurality of liquid sensors have conductive surfaces adapted to be electrically connected to one another by the fluid when said conductive surfaces are immersed in and in contact with the fluid to complete an electrical circuit such that current may pass between said conductive surfaces of each liquid sensor through the fluid in order to monitor the condition of the fluid, said plurality of vapor sensors are in direct contact with vapors of the fluid for measuring vapor parameters of the fluid, each of said plurality of vapor sensors comprising at least two conductive surfaces adapted to be electrically connected to one another by vapor of the fluid such that in use current passes between said conductive surfaces through the vapor

placing a portion of said member in the fluid such that said plurality of liquid sensors are immersed in and in contact with said fluid to make the electrical connection therebetween, and wherein said plurality of vapor sensors are in direct contact with the vapors of the fluid but do not come in contact with a liquid of the fluid;

measuring at least one parameter of said fluid by detecting current passing between said conductive surfaces of each liquid sensor through the fluid; and

determining a condition of said fluid selected from the group consisting of fluid level, viscosity, temperature, electrical conductivity, electrochemical activity, water contamination, wear metals, soot buildup, coolant contamination, capacitance, dielectric constant, and combinations thereof by analyzing measurements of said fluid using an algorithm based on said measurements of said plurality of liquid sensors and said plurality of vapor sensors.

30. A method as claimed in claim 29, wherein said method further comprises applying a square waveform to said fluid.

31. A method as claimed in claim 29, wherein said method further comprises applying a triangular waveform to said fluid.

32. A method as claimed in claim 29, wherein said method further comprises applying a sine waveform to said fluid.

33. A method as claimed in claim 29, wherein said method further comprises varying the temperature of the fluid.

34. A method as claimed in claim 29, further comprises displaying said condition of said fluid.