The limiting-current type gas sensor includes: a porous lower electrode disposed on a substrate; an insulating film disposed on the porous lower electrode; a solid electrolyte layer disposed on the porous lower electrode in an opening formed by patterning the insulating film, and further disposed on the insulating film surrounding the opening; and a porous upper electrode disposed on the solid electrolyte layer, wherein the insulating film realizes non-contact between an edge face of the solid electrolyte layer and the porous lower electrode, in order to suppress the intake of oxygen (O) ion from the edge face of the solid electrolyte layer, and thereby the surface-conduction current component between the porous upper electrode and the porous lower electrode can be reduced. There can be provided the limiting-current type gas sensor capable of reducing the surface-conduction current component and realizing low power consumption.

An electrochemical sensor is provided which may be formed using micromachining techniques commonly used in the manufacture of integrated circuits. This is achieved by forming microcapillaries in a silicon substrate and forming an opening in an insulating layer to allow environmental gases to reach through to the top side of the substrate. A porous electrode is printed on the top side of the insulating layer such that the electrode is formed in the opening in the insulating layer. The sensor also comprises at least one additional electrode. The electrolyte is then formed on top of the electrodes. A cap is formed over the electrodes and electrolyte. This arrangement may easily be produced using micromachining techniques.

The present disclosure relates to a method for operating an amperometric sensor for detecting measured values of at least one first measurand that represents a concentration of a first analyte in a measuring fluid, and of at least one second measurand which represents a concentration of a second analyte different from the first analyte. The method includes steps of detecting measured values of the first measurand in a first operating mode of the amperometric sensor, switching the amperometric sensor to a second operating mode different from the first operating mode, and detecting measured values of the second measurand in the second operating mode of the amperometric sensor. The method can be used in monitoring the water quality in drinking water installations or drinking water networks.

An array sensing electrode includes an electric insulating base plate, a plurality of electric conductive assemblies, a reference sensing layer, at least a chemical sensing layer, and an electrolyte layer. The electric insulating base plate has a plurality of perforations. Each electric conductive assembly includes an electric conductive filler, a first electric conductive part, and a second electric conductive part. The electric conductive filler is penetrated through the perforation, and the first electric conductive part and the second electric conductive part are disposed on a first plane and a second plane of the electric conductive filler, respectively. The reference sensing layer and the chemical sensing layer are disposed on different first electric conductive parts, and the electrolyte layer is disposed on the reference sensing layer and the chemical sensing layer to cover thereon. Therefore, the advantages of decreasing the manufacture cost and being conductive to packaging are achieved.

A method of testing a system, which has at least one electrochemical sensor for detecting an analyte gas within a housing of the system, and the housing has an inlet, includes exhaling in the vicinity of the inlet of the housing of the system and measuring a response to exhaled breath to test one or more transport paths of the system. Measuring the response to exhaled breath may, for example, include measuring the response of a sensor within the housing of the system that is responsive to the presence of exhaled breath. The sensor responsive to the presence of exhaled breath may, for example, include an electrochemically active electrode responsive to a gas within exhaled breath. The electrochemically active electrode may, for example, be responsive to carbon dioxide or to oxygen.

The present disclosure provides improved sensor assemblies for gases. More particularly, the present disclosure provides for gas sensor assemblies operating at high temperature. Improved high temperature sensor assemblies for reducing gas are provided. In some embodiments, the present disclosure provides advantageous impedancemetric high temperature gas sensor assemblies based on electrospun nanofibers and having selectivity towards reducing gas, and related methods of use. In exemplary embodiments, the present disclosure provides for impedancemetric high temperature gas sensor assemblies having selectivity towards reducing gas. In certain embodiments, the sensor assembly includes electrospun nanofibers. Impedancemetric techniques have been employed at high operating frequency (e.g., 10.sup.5 Hz) for the first time to provide real-time assemblies, methods and devices to sensitively and/or selectively detect reducing gas (e.g., CO, C.sub.3H.sub.8 (propane), etc.) at high temperatures (e.g., at about 800 C.).

In an embodiment, a hydrogen monitoring system comprises a plurality of sensing elements that individually comprise a working electrode, a counter electrode, an insulating layer located in between the working electrode and the counter electrode, a catalyst located on an end of both the working electrode and the counter electrode, an electrolyte located on the end of the sensing elements on both the working electrode and the counter electrode, between the working electrode and the counter electrode, and in contact with the catalyst, and an electrical circuit located on an opposite end of the sensing element that connects the working electrode and the counter electrode.

A carbon electrode having a functional moiety that forms a charge-transfer complex with a nitro-containing compound covalently attached to a surface of the electrode, and a process of preparing such an electrode are provided. Also provided are sensing systems integrating the carbon electrode and methods utilizing same for electrochemical detection of nitro-containing compounds.

Apparatus and associated methods relate to a compact gas sensor (CGS) including a housing with a central stepped cavity with one or more first lead contact(s) forming a portion of a base plane in a bottom of the cavity and one or more second lead contact(s) forming a portion of a stepped plane higher than the base plane, the cavity sized to receive a chemically based stack of material made up of a bottom diffusion electrode layer, a middle electrolyte gel layer, and a top diffusion electrode layer. The bottom diffusion electrode layer is in electrical contact with the first lead contact(s). The top diffusion electrode layer electrically couples to the second lead contact(s) via an overlaying micro electromechanical system (MEMS) element layer with conductive coating. In an illustrative example, the CGS may provide gas sensing in small spaces.

A sensing electrode, and an electrochemical system and method utilizing same for detecting peroxide-containing compounds in a sample, are provided. The sensing electrode is a carbon electrode having ions of a metal that promotes decomposition of a peroxide absorbed to its surface, optionally along with a solid electrolyte membrane.