Integral hydrolysis layer junction

• US 5,152,882 A
• Filed: 09/28/1990
• Issued: 10/06/1992
• Est. Priority Date: 09/28/1990
• Status: Expired due to Term

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Benton, Barry W.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Bell, Bruce F.
• Application Number:
  US07/589,936
• Time in Patent Office: 739 Days
• Field of Search: 204/435, 204/421, 204/416, 204/414
• US Class Current: 204/416
• CPC Class Codes: G01N 27/401 Salt-bridge leaks; Liquid junctions
• CPC Class Codes: G01N 27/4035 Combination of a single ion-sensing electrode and a single reference electrode G01N27/406 and G01N27/413 take precedence

Abstract

The present invention includes an ion diffusion junction in an electrochemical cell. The junction includes a polymer matrix that is impermeable to the sample solution. A plurality of inclusions are disposed within the junction matrix and oriented to form continuous hydrolytic pathways extending between the sample solution and the reference electrolyte such that ion diffusion occurs along the hydrolytic pathways.

Claims

1. A junction in an electrochemical cell, the junction having a sample solution facing surface and a reference electrolyte facing surface, the junction comprising:

a polymer matrix impermeable to the sample solution;

a plurality of inclusions disposed withinthe matrix and oriented to form continuous hydrolytic ion diffusion pathways extending between the sample solution facing surface and the electrolyte facing surface such taht ion diffusion occurs along the pathways without flow of the sample solution along the pathways; and

a hydrolyzable layer between the inclusions and the matrix.

2. The junction of claim 1 wherein the polymer matrix is a thermoplastic.

3. The junction of claim 1 wherein the inclusions are glass fibers.

4. The junction of claim 1 wherein the hydrolyzable coating is a silane.

5. An electrochemical cell sensor housing, the cell comprising:

a liquid impermeable housing wall defining a reference electrolyte enclosure;

an electrolyte disposed within the electrolyte enclosure;

an electrode in conductive relationship with the electrolyte;

a junction disposed within the housing wall, the junction comprising a polymer matrix having a plurality of inclusions disposed therein and a hydrolyzable layer between the inclusions and the matrix and the inclusions oriented to form continuous hydrolytic ion diffusion pathways that are in conductive relationship with the electrolyte and with a sample solution without flow of the sample solution along the pathways.

6. The cell of claim 5 wherein the wall is made of a thermoplastic.

7. The cell of claim 5 wherein the inclusions are glass fibers.

8. The cell of claim 5 wherein the hydrolyzable coating is a starch-like material.

9. The cell of claim 5 wherein the housing wall and the junction are integrally formed by injection molding.