Scalable process transmitter

• US 6,568,279 B2
• Filed: 04/18/2002
• Issued: 05/27/2003
• Est. Priority Date: 09/28/1999
• Status: Expired due to Term

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Schnaare, Theodore H., Hedtke, Robert C., Roper, Weston, Nelson, Richard L., Nelson, Scott D., Fandrey, Mark C., Behm, Steven M., Davis, Dale S., Schumacher, Mark S., Schulte, John P., Frick, Roger L.
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US10/125,286
• Publication Number:
  US 20020108448A1
• Time in Patent Office: 404 Days
• Field of Search: 737/05, 737/15--27, 737/06, 737/56, 737/53, 200/2, 200/67
• US Class Current: 73/756
• CPC Class Codes: G01D 1/00 Measuring arrangements giving results other than momentary value of variable, of general application G01D3/00 takes precedence; in tariff metering apparatus G01D4/00; transducers not specially adapted for a specific variable G01D5/00
• CPC Class Codes: G01L 13/026 involving double diaphragm
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 19/0663 Flame protection; Flame barriers
• CPC Class Codes: G01L 19/069 Protection against electromagnetic or electrostatic interferences
• CPC Class Codes: G01L 19/083 electrical
• CPC Class Codes: H01R 13/527 Flameproof cases H01R13/70 takes precedence
• CPC Class Codes: H01R 29/00 Coupling parts for selective co-operation with a counterpart in different ways to establish different circuits, e.g. for voltage selection, for series-parallel selection, programmable connectors
• CPC Class Codes: Y10S 439/912 with testing means
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A scalable process transmitter architecture includes a unitized sensor module and an optional scalable transmitter. The sensor module has a sensor output that is configurable which can connect locally to a scalable transmitter module to form a transmitter, or can be wired directly to a remote receiver. The scalable transmitter can mount on the unitized sensor module and generates a scalable output for a remote receiver. The transmitter module can provide more advanced features for specific applications.

Claims

1. A unitized sensor module, comprising:

a housing adapted for coupling to a process opening, the housing having an outer wall surrounding a cavity and having a fitting integral with the outer wall and adapted to support a scalable transmitter module, the fitting opening to the cavity;

a circuit disposed in the cavity, the circuit having a sensor coupling to the process opening and providing a sensor output; and

a feedthrough sealing the fitting and having external conductors extending therethrough for energizing the circuit and receiving the sensor output, the sensor output being configurable for local connection to a scalable transmitter module and configurable for direct wiring to a remote receiver.

2. The unitized sensor module of claim 1 further comprising an isolator configured to isolate fluid at the process opening from the sensor.

3. The unitized sensor module of claim 2, wherein the isolator includes a passageway to couple between the sensor and the process opening, the passageway having a shape which provides flameproofing.

4. The unitized sensor module of claim 1 wherein the fitting includes an outer surface adapted to seal to a scalable transmitter module.

5. The unitized sensor module of claim 1 wherein the feedthrough includes a capillary tube sealed to complete flameproofing of the feedthrough.

6. The unitized sensor module of claim 1 wherein the cavity is filled with a non flammable gas.

7. The unitized sensor module of claim 1 wherein the outer surface of the fitting further comprises a setscrew surface adapted to permit rotation of at least 360 degrees of a setscrew on a scalable transmitter module.

8. The unitized sensor module of claim 1 wherein the fitting extends around the external conductors and is adapted to retain a plug mating with the external conductors.

9. The unitized sensor module of claim 1 wherein the housing is formed of metal and has wall thickness of at least 2 millimeters thick and the housing is explosion proof.

10. The unitized sensor module of claim 1 wherein the housing includes a flange which couples to the process opening and also couples to a second process opening for sensing differential pressure.

11. The unitized sensor module of claim 1 wherein the local connection comprises a serial bus.

12. The unitized sensor module of claim 1 wherein the local connection comprises between three and five conductors.

13. The unitized sensor module of claim 1 wherein the circuit is configured to be powered from the local connection.

14. The unitized sensor module of claim 1 wherein the direct wiring comprises a two wire process control loop.

15. The unitized sensor module of claim 14 wherein the loop is in accordance with a 4-20 mA standard.

16. The unitized sensor module of claim 14 wherein the loop is in accordance with a digital communication standard.

17. The unitized sensor module of claim 1 wherein the module is intrinsically safe.

18. The unitized sensor module of claim 1 wherein the circuit provides a scalable sensor output.

19. A scalable transmitter module, comprising:

a housing adapted to mount on a unitized sensor module, the housing having an outer wall surrounding a cavity and including a removable cover for accessing the cavity, the housing having a first opening adapted to mount on a fitting of the unitized sensor module and a second opening adapted for connection to a wiring raceway to a remote receiver, and

a circuit in the cavity having a plug adapted to mate with a feedthrough of the unitized sensor module, the circuit being adapted to receive a sensor output from the unitized sensor module and generate a scalable output on circuit terminals accessible by removing the cover, the scalable output being adapted for transmission to the remote receiver.

20. The scalable transmitter module of claim 19 wherein the circuit includes a terminal block connecting the sensor output to the remote receiver.

21. The scalable transmitter module of claim 19 wherein the circuit is configured to transmit the sensor output on a two wire process control loop adapted for transmission to the remote receiver.

22. The scalable transmitter module of claim 19 wherein the removable cover includes a window and the circuit includes a display visible through the window.

23. The scalable transmitter module of claim 19 further comprising a display coupled to the circuit.

24. The scalable transmitter module of claim 19 wherein the circuit is configured to process a sensor output from the unitized sensor module.

25. The scalable transmitter module of claim 19 wherein the circuit is configured to couple to a second unitized sensor module.

26. The scalable transmitter module of claim 19 wherein the transmitter module is configured to be spaced apart from the unitized sensor module and the units are electrically coupled together.

27. The scalable transmitter module of claim 21 wherein the transmitter module is physically coupled to the feedthrough of the unitized sensor module.

28. The scalable transmitter module of claim 21 wherein the two wire process control loop is in accordance with a 4-20 mA standard.

29. The scalable transmitter module of claim 21 wherein the two wire process control loop is in accordance with a digital standard.

30. The scalable transmitter module of claim 21 wherein the scalable transmitter module and the unitized sensor module are completely powered from the two wire process control loop.

31. The scalable transmitter module of claim 19 wherein the circuit completely powers the unitized sensor module.