High integrity process fluid pressure probe

• US 9,841,338 B2
• Filed: 08/30/2016
• Issued: 12/12/2017
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Hedtke, Robert C., Sittler, Fred C.
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US15/251,066
• Publication Number:
  US 20160370240A1
• Time in Patent Office: 469 Days
• Field of Search: None
• CPC Class Codes: G01L 19/0023 for flowthrough systems having a flexible pressure transmitting element
• CPC Class Codes: G01L 19/0046 using isolation membranes G01L13/026 and G01L19/0645 take precedence
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 19/0645 using isolation membranes, specially adapted for protection
• CPC Class Codes: G01L 19/0672 Leakage or rupture protection or detection
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

A process fluid pressure measurement probe includes a pressure sensor formed of a single-crystal material and mounted to a first metallic process fluid barrier and disposed for direct contact with a process fluid. The pressure sensor has an electrical characteristic that varies with process fluid pressure. A feedthrough is formed of a single-crystal material and has a plurality of conductors extending from a first end to a second end. The feedthrough is mounted to a second metallic process fluid barrier and is spaced from, but electrically coupled to, the pressure sensor. The pressure sensor and the feedthrough are mounted such that the secondary metallic process fluid barrier is isolated from process fluid by the first metallic process fluid barrier.

Claims

1. A process fluid pressure measurement probe comprising:

a flange mountable to a process fluid conduit and having an aperture therethrough;

an inner conduit having a pair of ends, a first end being welded to the flange;

an outer conduit having a pair of ends, a first end being welded to the flange;

an isolator plug welded to a second end of the inner conduit and to a second end of the outer conduit, the isolator plug having a passageway therethrough;

an isolation diaphragm welded to the isolator plug, the isolation diaphragm being adapted for exposure to a process fluid;

a pressure sensor module welded to the isolator plug, the pressure sensor module defining a chamber therein and having a conduit in fluidic communication with the passageway of the isolator plug;

a pressure sensor mounted within the chamber, the pressure sensor having an electrical characteristic that varies with process fluid pressure;

a fill fluid surrounding the pressure sensor within the chamber, the fill fluid coupling pressure from the isolation diaphragm to the pressure sensor;

a plurality of leads coupled to the pressure sensor an extending therefrom through the aperture of the flange and being coupleable to a process pressure transmitter.

2. The process fluid pressure measurement probe of claim 1, and further comprising a process interface screen attached to the isolator plug and surrounding the isolation diaphragm.

3. The process fluid pressure measurement probe of claim 1, and further comprising a strain gauge mounted to an internal surface of the inner conduit.

4. The process fluid pressure measurement probe of claim 1, wherein the pressure sensor includes a temperature sensor therein.

5. The process fluid pressure measurement probe of claim 1, and further comprising a process fluid pressure transmitter coupled to the pressure sensor and configured to transmit an indication of process fluid pressure over a process control loop.

6. A process fluid pressure measurement probe comprising:

a pressure sensor mounted to a first metallic process fluid barrier and having an electrical characteristic that varies with process fluid pressure;

a feedthrough formed of a single crystal material and having a plurality of conductors extending from a first end to a second end, the feedthrough being mounted to a second metallic process fluid barrier and being spaced from, but electrically coupled to, the pressure sensor; and

wherein the pressure sensor and the feedthrough are mounted such that the secondary metallic process fluid barrier is isolated from process fluid by the first metallic process fluid barrier.

7. The process fluid pressure measurement probe of claim 6, wherein the pressure sensor is formed of a single crystal material.

8. The process fluid pressure measurement probe of claim 6, wherein the pressure sensor is adapted for direct contact with a process fluid.