Variable fluid and tilt level sensing probe system

• US 5,423,214 A
• Filed: 04/04/1994
• Issued: 06/13/1995
• Est. Priority Date: 02/01/1993
• Status: Expired due to Term

• Current Assignee: Dilli Technology, Inc.
• Original Assignee: Calvin S. Lee
• Inventors: Lee, Calvin S.
• Primary Examiner(s): GUTIERREZ, DIEGO F
• Application Number:
  US08/222,169
• Time in Patent Office: 435 Days
• Field of Search: 73/304 C, 324/665, 324/662, 324/669, 324/671
• US Class Current: 73/304.00C
• CPC Class Codes: G01C 2009/062 capacitive
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container
• CPC Class Codes: G01F 22/00 Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for
• CPC Class Codes: G01F 23/265 for discrete levels
• CPC Class Codes: G01F 23/268 mounting arrangements of probes
• CPC Class Codes: G01F 23/80 Arrangements for signal processing

Abstract

Digital tilt level sensing probe system comprising a set of multiple capacitor elements in a fluid container arranged along an axis of measurement where each multiple capacitor element represents a discrete level increment in dielectric material fluid to be measured. Individual capacitors in each element are horizontally spaced to reflect a level differential upon tilting of the fluid container from its normal attitude. In the case of a probe for sensing tilting in a single plane, a one-piece body is employed to include integral capacitor elements, mounting pad, connector, custom IC pad, and circuitry molded into such body. Alternative references may be employed for comparison with each capacitor assigned a unique time slot in a switching sequence.

Claims

1. Digital fluid level sensing probe for use in a fluid container comprising a set of capacitors arranged along an axis of measurement where each capacitor represents a discrete level increment in a horizontal plane of dielectric fluid to be measured, each capacitor comprising a pair of individual, electrically, isolated capacitor elements, each individually subject to dielectric fluid which is present at its level and having sensible differential capacitance readable relative to a reference having an intermediate threshold value as to presence or absence of said fluid when addressed in a sequential individual tinge slot for each capacitor, plural individual capacitors at each level being spaced horizontally in columns to sense differentially fluid presence and absence upon tilting of the container from its normal attitude the arrangement of said plural individual capacitors providing memos to compensate for volumetric differentials incident to container tilting which is programmed relative to container configuration for enhanced accuracy of sensing volume indicated by fluid level.

2. Probe of claim 1 wherein said horizontal spacing is in a single plane subject to tilting differential of fluid presence at the individual capacitors of each level.

3. Probe of claim 2 wherein said probe comprises a one-piece body having two opposed sides joined by an integral connector, facing surfaces of each side having opposed adjacent capacitor elements spaced to accommodate intermediate dielectric fluid up to the fluid level in the container.

4. Probe of claim 3 including a custom integrated circuit pad applied to the outer surface of one of said sides.

5. Probe of claim 3 including an integral mounting pad for attachment of said one-piece body to the bottom surface of said container.

6. Probe of claim 3 wherein an outer surface of said one-piece body is metalized to provide shielding.

7. Probe of claim 1 including at least three of said plural individual capacitors at each level being spaced circumferentially to sense differentially fluid presence and absence upon tilting of the container in any direction.

8. Digital fluid level sensing probe for use in a fluid container comprising a set of capacitors arranged along an axis of measurement where each capacitor represents a discrete level increment in dielectric fluid to be measured, said capacitors being electrically isolated, each individually subject to dielectric fluid which is present at its level and having sensible differential capacitance readable relative to a reference having an intermediate threshold value as to presence or absence of said fluid when addressed in sequential individual time slots for each capacitor, said probe having a one-piece body, said body including opposed, spaced apart side portions and a connecting portion extending longitudinally in the axis of measurement continuously connecting said side portions, facing surfaces of said side portions having said capacitors secured thereon and said capacitors include opposed printed circuit capacitor elements spaced to accommodate intermediate dielectric fluid up to the fluid level in the container, said body having an integral mounting pad.

9. Probe of claim 8 including a custom integrated circuit pad applied to the outer surface of one of said side portions.

10. Probe of claim 8 wherein a surface, of said body is metalized to provide shielding.

11. Probe of claim 8 including terminals provided in said with circuitry being brought into said one-piece body up to the terminals in said connecting portion.

12. Probe of claim 8 wherein said set of capacitors further includes at least three capacitors at each level being spaced circumferentially to sense differentially fluid presence and absence upon tilting of the container in any direction.

13. Digital fluid level sensing probe for use in a fluid container comprising a set of capacitors arranged along an axis of measurement where each capacitor represents a discrete level increment in dielectric fluid to be measured, and having sensible differential capacitance readable relative to a reference having an intermediate threshold value as to presence or absence of said fluid when addressed in sequential individual time slots for each capacitor, said probe having a one-piece body, said body including opposed, spaced apart side portions and a connecting portion extending longitudinally in the axis of measurement continuously connecting said side portions, facing surfaces of said side portions having said capacitors secured to said facing surfaces and said capacitors include opposed printed circuit capacitor elements spaced to accommodate intermediate dielectric fluid up to the fluid level in the container, one side portion of said body having said capacitor elements formed as discrete isolated capacitor elements and a second side portion of said body having said capacitor elements formed as a common electrode, said body having an integral mounting pad.

14. Digital fluid level sensing probe for use in a fluid container comprising a set of capacitors arranged along an axis of measurement where each capacitor represents a discreet level increment in dielectric fluid to be measured, said capacitors being electrically isolated, each individually subject to dielectric fluid which is present at its level and having sensible differential capacitance readable relative to a reference having an intermediate threshold value as to presence or absence of said fluid when addressed in sequential individual time slots for each capacitor, said probe having a one-piece body, said body including opposed spaced apart side portions and a connecting portion extending longitudinally in the axis of measurement connecting said side portions, said side portions being arcuate and parallel, facing surfaces of said side portions having said capacitors secured thereon and said capacitors including opposed circuit capacitor elements spaced to accommodate intermediate dielectric fluid up to the fluid level in the container wherein said set of capacitors includes at least three individual capacitors at each level being spaced circumferentially to sense differential fluid presence and absence upon tilting of the container in any direction.

15. Digital fluid level sensing probe for use in a fluid container comprising a set of capacitors arranged along an axis of measurement where each capacitor represents a discrete level increment in dielectric fluid to be measured, said capacitors being electrically isolated, each individually subject to dielectric fluid which is present at its level and having sensible differential capacitance readable relative to a reference having an intermediate threshold value as to presence or absence of said fluid when addressed in sequential individual time slots for each capacitor, said probe having a one-piece body with two opposed sides jointed by an integral connector, facing surfaces of said sides having said capacitors secured thereon and said capacitors include opposed printed circuit capacitor elements spaced to accommodate intermediate dielectric fluid up to the fluid level in the container, said body having an integral mounting pad, and at least three capacitors of said set of capacitors at each level being spaced circumferentially to sense differentially fluid presence and absence upon tilting of the container in any direction.