Calibration structure for flex fuel sensor

• US 8,274,298 B2
• Filed: 11/10/2009
• Issued: 09/25/2012
• Est. Priority Date: 11/10/2009
• Status: Active Grant

• Current Assignee: Vitesco Technologies USA, LLC (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Woods, Ralf, VanZuilen, David, Nodine, Thomas
• Primary Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US12/615,287
• Publication Number:
  US 20110109323A1
• Time in Patent Office: 1,050 Days
• Field of Search: 324/601
• US Class Current: 324/601
• CPC Class Codes: G01N 27/228 Circuits therefor measuring capacitance per se G01R27/26
• CPC Class Codes: G01N 33/2852 Alcohol in fuels

Abstract

A calibration structure (10) for calibrating a flex fuel sensor (12) for a vehicle is provided. The flex fuel sensor has a first sensor electrode (14) and a second sensor electrode (16). The calibration structure includes a first electrode (30), a second electrode (36) spaced from and electrically insulated from the first electrode, and at least one capacitor (40), or at least one resistor (42), or at least one combination of a capacitor with a resistor, of a certain value electrically connected with the first and second electrodes. The first electrode (30) is constructed and arranged to contact the first sensor electrode (16) and the second electrode (36) is constructed and arranged to contact the second sensor electrode (14) to provide a known input value to the flex fuel sensor for calibration of the flex fuel sensor without the use of test liquids.

Claims

1. A calibration structure for calibrating a flex fuel sensor for a vehicle, the flex fuel sensor having a first sensor electrode and a second sensor electrode, the calibration structure comprising:

a first electrode,

a second electrode spaced from and electrically insulated from the first electrode, and

at least one capacitor, or at least one resistor, or at least one combination of a capacitor with a resistor, of a certain value electrically connected with the first and second electrodes,

wherein the first and second electrodes are separated from the first and second sensor electrodes and wherein the first electrode is constructed and arranged to be moved into contact with the first sensor electrode and the second electrode is constructed and arranged to be moved into contact with the second sensor electrode to provide a known input value to the flex fuel sensor for calibration of the flex fuel sensor without the use of test liquids.

2. The calibration structure of claim 1, wherein the second electrode has an outer, generally cylindrical periphery that is larger than an outer periphery of the first electrode.

3. The calibration structure of claim 1, further comprising a body having proximal and distal ends, the first and second electrodes being associated with the body, the first electrode being disposed generally at the distal end of the body.

4. The calibration structure of claim 3, wherein the body includes a first portion at the proximal end defining a handle constructed and arranged to be grasped by a user, and a second, elongated portion extending from the handle to the distal end.

5. The calibration structure of claim 4, wherein the elongated portion is a tubular member having an inner channel, the first electrode being disposed in the channel such that a portion of the first electrode extends outwardly from the tubular member and the second electrode is disposed about a periphery of the tubular member.

6. The calibration structure of claim 3, wherein the capacitor, the resistor, or the combination of a capacitor with a resistor is disposed within the body.

7. The calibration structure of claim 4, wherein the capacitor, the resistor, or the combination of a capacitor with a resistor is disposed within the handle.

8. The calibration structure of claim 3, wherein the capacitor, the resistor, or the combination of a capacitor with a resistor is disposed outside of the body and in a separate structure.

9. The calibration structure of claim 8, wherein a plurality of different value capacitors and a plurality different value resistors are provided in the separate structure, the calibration structure including switching structure associated with the capacitors and resistors to selectively switch between the capacitors, or between the resistors, or between combinations of the capacitors and resistors, to provide the known input value.

10. The calibration structure of claim 1, further comprising spring structure to bias the first and second electrodes to ensure contact with the first and second sensor electrodes, respectively.

11. The calibration structure of claim 1, in combination with the fuel flex sensor, wherein the first electrode removably contacts the first sensor electrode and the second electrode removably contacts the second sensor electrode.

12. A method of calibrating a flex fuel sensor for a vehicle, the flex fuel sensor having a first sensor electrode and a second sensor electrode, the method comprising:

providing a calibration structure comprising a first electrode, a second electrode spaced from and electrically insulated from the first electrode, and at least one capacitor, or at least one a resistor, or at least one combination of a capacitor with a resistor, of a certain value electrically connected with the first and second electrodes, and

moving the calibration structure so that the first electrode makes electrical contact with the first sensor electrode and the second electrode makes electrical contact with the second sensor electrode thereby providing a known input value to the fuel flex sensor for use in calibrating the fuel flex sensor absent the use of test liquids.

13. The method of claim 12, wherein a single capacitor is provided having the certain value that represents a capacitance of a certain test liquid such that the known input value is a capacitance value.

14. The method of claim 12, wherein a single resistor is provided having the certain value that represents a conductance of a certain test liquid such that the known input value is a conductance value.

15. The method of claim 12, further comprising providing a plurality of calibration structures with each calibration structure being constructed and arranged to emulate a known capacitance or conductance value of a test liquid.

16. The method of claim 12, wherein a plurality of different value capacitors and a plurality of different value resistors are provided together with switching structure, the method further comprises:

selectively switching between the capacitors, or between the resistors, or between combinations of the capacitors and resistors, to provide the known input value.

17. The method of claim 12, wherein the step of providing calibration structure includes providing a body having an elongated tubular member, the first electrode having a portion extending from a distal end of the tubular member, the second member being disposed about a periphery of the tubular member.

18. The method of claim 12, further comprising biasing the first and second electrodes as to maintain contact with the respective first and second sensor electrodes.

19. A calibration structure for calibrating a flex fuel sensor for a vehicle, the flex fuel sensor having a first sensor electrode and a second sensor electrode, the calibration structure comprising:

a first electrically conductive member,

a second electrically conductive member spaced from and electrically insulated from the first electrically conductive member, and

means for providing capacitance, or resistance, or a combination of a capacitance and resistance, of a certain value through the first and second electrically conductive members,

wherein the first and second electrically conductive members are separated from the first and second sensor electrodes and wherein the first electrically conductive member is constructed and arranged to be moved into contact with the first sensor electrode and the second electrically conductive member is constructed and arranged to be moved into contact with the second sensor electrode to provide a known input value to the flex fuel sensor for calibration of the flex fuel sensor without the use of test liquids.

20. The calibration structure of claim 19, wherein the means for providing is a separate capacitor, or a separate resistor, or a combination of a separate capacitor and separate resistor, electrically connected with the first and second electrically conductive members.