Differential pressure measuring probe with bottoming indicator

• US 7,561,056 B2
• Filed: 03/27/2007
• Issued: 07/14/2009
• Est. Priority Date: 03/27/2007
• Status: Active Grant

• Current Assignee: Dieterich Standard, Inc. (Emerson Electric Company)
• Original Assignee: Dieterich Standard, Inc. (Emerson Electric Company)
• Inventors: McMillan, David T.
• Primary Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US11/692,009
• Publication Number:
  US 20080238697A1
• Time in Patent Office: 840 Days
• Field of Search: 340/603, 340/611, 737/00, 737/56
• US Class Current: 340/603
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/46 Pitot tubes

Abstract

A bottoming indication system indicates contact between an inner wall of a fluid conducting conduit and a tip of a differential pressure measuring probe. The system includes a piezoelectric device and an indicator. The piezoelectric device is affixed to the tip of the differential pressure measuring probe so that pressure exerted on the piezoelectric device by contact between the piezoelectric device and the inner wall of the conduit produces a voltage difference across the piezoelectric device. The indicator is in electrical communication with the piezoelectric device so that a voltage difference across the piezoelectric device activates the indicator to indicate contact between the inner wall of the conduit and the tip of the differential pressure measuring probe.

Claims

1. A bottoming indication system for indicating contact between an inner wall of a fluid conducting conduit and a tip of a differential pressure measuring probe, the system comprising:

a piezoelectric device affixed to the tip of the differential pressure measuring probe wherein pressure exerted on the piezoelectric device by contact between the piezoelectric device and the inner wall of the conduit produces a voltage difference across the piezoelectric device;

an indicator in electrical communication with the piezoelectric device wherein a voltage difference across the piezoelectric device activates the indicator to indicate contact between the inner wall of the conduit and the tip of the differential pressure measuring probe.

2. The system of claim 1 wherein the piezoelectric device includes a piezo film sensor element.

3. The system of claim 1 wherein the piezoelectric device includes a piezoresistive pressure sensor.

4. The system of claim 1 wherein the indicator includes a visual indicator.

5. The system of claim 1 wherein the indicator includes an audible indicator.

6. The system of claim 1 further including a power supply in electrical communication with the piezoelectric device for supplying electrical power to the piezoelectric device.

7. The system of claim 1 further including an electrical signal amplifier in electrical communication between the indicator and the piezoelectric device.

8. The system of claim 5 further including a power supply in electrical communication with the electrical signal amplifier for supplying electrical power to the electrical signal amplifier.

9. The system of claim 1 further including electrical conductors for providing the electrical communication between the piezoelectric device and the indicator.

10. The system of claim 9 wherein the differential pressure measuring probe further includes:

an elongated body having upstream and downstream faces;

at least first and second fluid carrying plenums within the body;

a longitudinal passage within the body;

at least one opening in the upstream face of the body, each opening in fluid communication with the first fluid conducting plenum;

at least one opening in the downstream aspect of the body, each opening in fluid communication with the second fluid conducting plenum; and

wherein the electrical conductors are disposed in the longitudinal passage.

11. A differential pressure measuring probe for insertion into a fluid conducting conduit having an inner wall, the probe comprising:

an elongated body having upstream and downstream faces and a tip;

at least first and second fluid carrying plenums within the body;

at least one opening in the upstream face of the body, each opening in fluid communication with the first fluid conducting plenum;

at least one opening in the downstream aspect of the body, each opening in fluid communication with the second fluid conducting plenum;

a piezoelectric device affixed to the tip of the body wherein pressure exerted on the piezoelectric device by contact between the piezoelectric device and the inner wall of the conduit produces a voltage difference across the piezoelectric device;

an indicator in electrical communication with the piezoelectric device wherein a voltage difference across the piezoelectric device activates the indicator to indicate contact between the inner wall of the conduit and the tip of the differential pressure measuring probe.

12. The system of claim 11 wherein the piezoelectric device includes a piezo film sensor element.

13. The system of claim 11 wherein the piezoelectric device includes a piezoresistive pressure sensor.

14. The system of claim 11 wherein the indicator includes a visual indicator.

15. The system of claim 11 wherein the indicator includes an audible indicator.

16. The system of claim 11 further including a power supply in electrical communication with the piezoelectric device for supplying electrical power to the piezoelectric device.

17. The system of claim 11 further including an electrical signal amplifier in electrical communication between the indicator and the piezoelectric device.

18. The system of claim 11 further including a power supply in electrical communication with the electrical signal amplifier for supplying electrical power to the electrical signal amplifier.

19. The system of claim 11 further including electrical conductors for providing the electrical communication between the piezoelectric device and the indicator.

20. The system of claim 19 wherein the body further includes a longitudinal passage within the body and wherein the electrical conductors are disposed in the longitudinal passage.