Detection of refrigerant contaminants
First Claim
1. A method of preconditioning for the detection of contaminants in a refrigerant sensor comprising a housing, a membrane electrode assembly disposed in the housing, the membrane electrode assembly comprising a first catalyst comprising noble metal nanoparticles that are unsupported or are supported on a non-carbon black support, a counter electrode comprising a second catalyst comprising noble metal nanoparticles, and a solid polymer electrolyte disposed between the sensing electrode and the counter electrode, a first current collector in electrical contact with the sensing electrode, a second current collector in electrical contact with the counter electrode, a first flow field in fluid communication with a first opening in the housing to direct test refrigerant to flow by or through the sensing electrode, the housing including a chamber to which the counter electrode is exposed, and an electrical circuit connecting the sensing electrode and the counter electrode, the method comprising applying a positive voltage bias to the sensing electrode and exposing the sensor to a preconditioning gas comprising the contaminant(s) or their precursors or derivatives.
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Accused Products
Abstract
A gas sensor for detecting one or more contaminants in a refrigerant includes a housing having disposed therein a membrane electrode assembly comprising a sensing electrode, a counter electrode, and a solid polymer electrolyte disposed between the sensing electrode and the counter electrode. The sensing electrode comprises nanoparticles of a first catalyst comprising noble metal. The counter electrode comprises nanoparticles of a second catalyst comprising noble metal. The sensing electrode in the sensor has been preconditioned by exposure under a positive voltage bias to a preconditioning gas comprising the contaminant(s) or their precursors or derivatives.
12 Citations
18 Claims
- 1. A method of preconditioning for the detection of contaminants in a refrigerant sensor comprising a housing, a membrane electrode assembly disposed in the housing, the membrane electrode assembly comprising a first catalyst comprising noble metal nanoparticles that are unsupported or are supported on a non-carbon black support, a counter electrode comprising a second catalyst comprising noble metal nanoparticles, and a solid polymer electrolyte disposed between the sensing electrode and the counter electrode, a first current collector in electrical contact with the sensing electrode, a second current collector in electrical contact with the counter electrode, a first flow field in fluid communication with a first opening in the housing to direct test refrigerant to flow by or through the sensing electrode, the housing including a chamber to which the counter electrode is exposed, and an electrical circuit connecting the sensing electrode and the counter electrode, the method comprising applying a positive voltage bias to the sensing electrode and exposing the sensor to a preconditioning gas comprising the contaminant(s) or their precursors or derivatives.
Specification