Automated mechanical integrity verification

• US 7,692,539 B2
• Filed: 12/28/2006
• Issued: 04/06/2010
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C.
• Primary Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US11/648,197
• Publication Number:
  US 20080157987A1
• Time in Patent Office: 1,195 Days
• Field of Search: 340/603, 340/540, 737/56, 737/53
• US Class Current: 340/540
• CPC Class Codes: G01L 27/007 Malfunction diagnosis, i.e. diagnosing a sensor defect

Abstract

A process transmitter for sensing a process variable of a process fluid includes a process sensor, transmitter circuitry, a transmitter housing and a transmitter mounting component. The process sensor senses the process variable of the process fluid and the transmitter circuitry processes a signal from the process sensor. The transmitter housing receives the process sensor and transmitter circuitry, and the transmitter mounting component isolates the sensor or the transmitter circuitry from the process fluid or external environment. The mechanical integrity sensor validates assembly of the transmitter housing and transmitter mounting component.

Claims

1. A process transmitter for measuring a process variable, the process transmitter comprising:

a process sensor for sensing the process variable of a process fluid;

transmitter circuitry for processing a signal from the process sensor;

a transmitter housing for receiving the process sensor and transmitter circuitry;

at least one transmitter mounting component for isolating the sensor or the transmitter circuitry from the process fluid or external environment; and

a mechanical integrity sensor for validating assembly of the transmitter housing and transmitter mounting component, wherein the transmitter mounting component comprises a process flange for joining the transmitter housing with the process fluid;

wherein the mechanical integrity sensor comprises a material verification sensor for sensing material properties of the process flange, the material verification sensor comprising an active sensor system that generates;

an input signal corresponding to a spatial relationship between the transmitter housing and the transmitter mounting component; and

an output signal corresponding to a change in the input signal due to a change in the spatial relationship.

2. The process transmitter for measuring a process variable of claim 1 wherein:

the active sensor system includes an inductive proximity sensor;

the input signal comprises an eddy current between the transmitter housing and the transmitter mounting component; and

the change in the input signal comprises a change in an amplitude of oscillation of the eddy current due to a change in the spatial relationship.

3. A process transmitter for measuring a process variable, the process transmitter comprising:

a process sensor for sensing the process variable of a process fluid;

a transmitter housing for receiving the process sensor;

a process flange for joining the transmitter housing with a process fluid source; and

a mechanical integrity sensor for verifying material properties of the process flange.

4. The process transmitter of claim 3 wherein the mechanical integrity sensor comprises an inductive permeability sensor.

5. The process transmitter of claim 4 wherein the inductive permeability sensor comprises:

an inductance coil for generating an electrostatic field positioned within the sensor housing adjacent a housing cover;

a core material positioned within the inductance coil;

an oscillator for generating an eddy current in the core; and

a signal level detector for sensing a change in an amplitude of oscillation of the eddy current when the process flange is positioned near the core.

6. The process transmitter of claim 3 and further comprising a second material verification sensor for sensing material properties of a process diaphragm positioned within the process transmitter.

7. The process transmitter of claim 3 and further comprising transmitter circuitry including predetermined material property values for comparison to a signal generated by the mechanical integrity sensor.

8. The process transmitter of claim 7 and further comprising electronic circuitry that annunciates when the signal generated by the mechanical integrity sensor differs from a predetermined material property value.

9. A process transmitter for measuring a process variable, the process transmitter comprising:

a process sensor for sensing the process variable of a process fluid;

transmitter circuitry for processing a signal from the process sensor;

a transmitter housing for receiving the process sensor and transmitter circuitry;

at least one transmitter mounting component for isolating the sensor or the transmitter circuitry from the process fluid or external environment; and

a mechanical integrity sensor for validating assembly of the transmitter housing and transmitter mounting component;

wherein the mechanical integrity sensor comprises a material verification sensor for sensing a material property of the transmitter mounting component; and

wherein the transmitter mounting component comprises a process flange for joining the transmitter housing with the process fluid.

10. The process transmitter of claim 9 wherein the transmitter circuitry includes predetermined values for comparison to a signal generated by the mechanical integrity sensor.

11. The process transmitter of claim 9 wherein the transmitter circuitry validates the sensed material property of the process flange with material property data stored in the transmitter circuitry.

12. The process transmitter of claim 9 wherein the material verification sensor comprises an inductive permeability sensor.

13. The process transmitter of claim 9 and further comprising a second material verification sensor for sensing material properties of a process diaphragm positioned within the process transmitter.

14. The process transmitter of claim 9 wherein the transmitter circuitry includes electronics that annunciate to a user output of the mechanical integrity sensor.

15. The process transmitter of claim 9 wherein the transmitter circuitry operates the mechanical integrity sensor as a continuous background operation.

16. The process transmitter of claim 9 wherein the transmitter circuitry includes a user control such that a user is able to manually initiate operation of the mechanical integrity sensor.

17. The process transmitter for measuring a process variable of claim 9 wherein the mechanical integrity sensor comprises an analog sensor.