Electrochemical gas sensor for the detection of nitric oxide

• US 5,565,075 A
• Filed: 06/06/1995
• Issued: 10/15/1996
• Est. Priority Date: 06/06/1995
• Status: Expired due to Term

• Current Assignee: Mine Safety Appliances Co LLC (MSA Safety, Inc.), MSA Technology, LLC (MSA Safety, Inc.)
• Original Assignee: Mine Safety Appliances Company (MSA Safety, Inc.)
• Inventors: Scheffler, Towner B., Davis, Brian K.
• Primary Examiner(s): TUNG, TA HSUNG
• Application Number:
  US08/469,338
• Time in Patent Office: 497 Days
• Field of Search: 204/153.18, 204/415, 204/412, 204/431, 204/291, 204/292, 205/781
• US Class Current: 204/412
• CPC Class Codes: G01N 27/4045 for gases other than oxygen

Abstract

The present invention provides electrochemical sensors for the detection of nitric oxide comprising a housing in which is disposed a working electrode, a reference electrode and a counter electrode. The electrochemically active surface of the working electrode preferably comprises RuO₂. The nitric oxide electrochemical sensors of the present invention are capable of resolving nitric oxide concentrations at least as low as approximately 0.1 ppm and are well suited for use in medical environments because of their insensitivity to many other gases commonly used in medical environments.

Claims

1. An electrochemical gas sensor for the detection of nitric oxide, comprising:

a housing, the housing having disposed therein a working electrode, a reference electrode and a counter electrode, an electrochemically active surface of the working electrode comprising a material selected from the group consisting of Ru and RuO₂, electrical connection being maintained between the working electrode and the counter electrode via an electrolyte present within the housing, the electrochemical gas sensor further comprising circuitry maintaining the working electrode at a potential in the range of approximately 1000 to 1500 mV versus a normal hydrogen electrode such that the working electrode is suitable for oxidizing nitric oxide.

2. The electrochemical gas sensor of claim 1, wherein an electrochemically active surface of the reference electrode comprises an electrochemically active material selected from the group consisting of an electrically conductive carbon, platinum, iridium and a mixture of silver and silver sulfate.

3. The electrochemical gas sensor of claim 1, wherein an electrochemically active surface of the counter electrode comprises an electrochemically active material selected from the group consisting of an electrically conductive carbon, platinum and iridium.

4. The electrochemical gas sensor of claim 1, wherein the electrochemically active surface of the working electrode comprises RuO₂.

5. The electrochemical gas sensor of claim 4, wherein the reference electrode comprises platinum.

6. The electrochemical gas sensor of claim 4, wherein the counter electrode comprises platinum.

7. The electrochemical gas sensor of claim 1, wherein the circuitry maintains the working electrode at a potential in the range of approximately 1250 to 1350 mV versus the normal hydrogen electrode.