Measuring device having a plurality of potentiometric electrode pairs situated on a substrate

• US 20050151541A1
• Filed: 12/17/2004
• Published: 07/14/2005
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Brinz, Thomas, Lewis, Jane
• Granted Patent: US 7,378,852 B2
• Time in Patent Office: Days
• US Class Current: 324/438
• CPC Class Codes: G01N 27/4162 investigating the composition of gases, by the influence exerted on ionic conductivity in a liquid conductometry in general G01N27/06; amperometric gas sensors G01N27/404

Abstract

A measuring device having a plurality of potentiometric electrode pairs situated on a substrate is described. One of the electrodes of each electrode pair represents a reference electrode and the other electrode represents a pH-sensitive working electrode. The electrode pairs form an interdigital structure, and the substrate is covered by a mask in such a way that the individual electrode pairs are separated from one another at least in the area of the interdigital structures of the electrode pairs.

Claims

1. A measuring device, comprising:

a substrate;

a mask; and

a plurality of potentiometric electrode pairs situated on the substrate, one of the electrodes of each electrode pair representing a reference electrode and the other electrode representing a pH-sensitive working electrode, wherein;

the electrode pairs in each case form an interdigital structure, and

the substrate is covered by a mask in such a way that the individual electrode pairs are separated from one another at least in an area of the interdigital structure of the electrode pairs.

2. The measuring device as recited in claim 1, wherein the mask is designed such that a cavity delimited by the mask is formed over each interdigital structure.

3. The measuring device as recited in claim 1, further comprising:

chemically inert gaskets provided between the mask and the electrodes and between the mask and the substrate.

4. The measuring device as recited in claim 3, wherein the gaskets are made of one of fluorinated rubber and tetrafluoroethylene.

5. The measuring device as recited in claim 1, wherein:

the mask is made of one of a synthetic material, stainless steel, and glass, and

the mask has openings in an area of the interdigital structure and electrical contact points electrodes of the electrode pairs exposing the interdigital structures and the contact points.

6. The measuring device as recited in claim 5, wherein the interdigital structures are provided with a cover layer in an area of the openings, the cover layer chemically isolating the interdigital structure from a medium to be tested and permitting a pH value to be determined.

7. The measuring device as recited in claim 6, wherein the cover layer includes one of a polymer electrolyte and a porous glass diaphragm.

8. The measuring device as recited in claim 1, wherein substrate is a ceramic substrate, and wherein the electrodes of the electrode pairs are made of materials which can be applied to the ceramic substrate using screen printing.

9. The measuring device as recited in claim 8, wherein the working electrode is includes one of an IrO₂electrode and an SbO electrode.

10. The measuring device as recited in claim 8, wherein the reference electrode includes one of an AgCl/Ag electrode and an AgBr/Ag electrode.