Amperometric measuring device having an electrochemical sensor
First Claim
1. An amperometric sensor device for measuring the content of an oxygen reducible substance in a liquid, having in combination a sensor having a planar structure obtained by photolithograpic techniques and a circuit for measuring the intensity of the electrochemical current generated by said sensor, said structure comprisingan insulating substratea set of electrodes composed of at least one working electrode., one counter electrode and one reference electrode, at least said working electrode being disposed on said insulating substrate,said working electrode having an active surface only defined by a conductive part at the surface of said substrate, said device further comprising a diffusion membrane covering said conductive part of said working electrode While Overlapping the entire periphery of said conductive part, andconnection means to connect said electrodes to said measuring circuit,said diffusion membrane, said reference electrode and said counter electrode being entirely exposed so that, when said device is functioning, they are in contact over their entire surfaces with the liquid to be analyzed.
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Accused Products
Abstract
An amperometric sensor device comprises in combination a sensor (21) having a planar structure obtained by photolithographic techniques and a circuit (22) for measuring the intensity of the electrochemical current generated by the sensor (21). The planar structure has an insulating substrate (23 to 25) and a set of electrodes composed of a working electrode (29), a counter electrode (30) and a reference electrode (31). A diffusion membrane (32) is deposited on the working electrode (29). Connection means (26) are provided to connect the electrodes (29,30,31) to the measuring circuit (22). According to the invention, the active conducting part of the working electrode (29), situated at the surface of the substrate (23) is entirely covered by the diffusion membrane (32) which overlaps this electrode (29) over its entire peripheral zone, whereas this membrane is entirely exposed so that, during the operation of the device (20) it is in contact with the fluid to be analysed over its entire surface.
The invention has applications in measuring the content of an oxygen reducible substance in a fluid, notably of chlorine in drinking water.
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Citations
12 Claims
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1. An amperometric sensor device for measuring the content of an oxygen reducible substance in a liquid, having in combination a sensor having a planar structure obtained by photolithograpic techniques and a circuit for measuring the intensity of the electrochemical current generated by said sensor, said structure comprising
an insulating substrate a set of electrodes composed of at least one working electrode., one counter electrode and one reference electrode, at least said working electrode being disposed on said insulating substrate, said working electrode having an active surface only defined by a conductive part at the surface of said substrate, said device further comprising a diffusion membrane covering said conductive part of said working electrode While Overlapping the entire periphery of said conductive part, and connection means to connect said electrodes to said measuring circuit, said diffusion membrane, said reference electrode and said counter electrode being entirely exposed so that, when said device is functioning, they are in contact over their entire surfaces with the liquid to be analyzed.
Specification