Electrochemical gas sensor with reduced wake-up time
An electrochemical gas sensor that includes a wick held in contact with an electrode substrate having at least a working electrode and a counter electrode by a spreader plate. The spreader plate is formed as a planar element that includes a series of perforations to reduce the rigidity of the spreader plate. The perforated spreader plate is held in contact with the wick by a pair of spring arms to bias the wick into contact with the electrodes formed on the substrate.
1 . An electrochemical gas sensor, comprising:
a housing having a reservoir for receiving an electrolyte;
a substrate extending across the housing and including at least a working electrode and a counter electrode;
a wick positioned within the housing and extending into the reservoir to contact the electrolyte, the wick being in contact with the working and counter electrodes of the substrate; and
a spreader plate positioned within the housing and in contact with the wick to hold the wick in contact with the substrate, wherein the spreader plate is a planar member having a plurality of perforations formed therein.
2 . The gas sensor of claim 1 wherein the spreader plate contacts the wick to define a generally planar contact portion of the wick, wherein the contact portion of the wick contacts the working and counter electrodes.
3 . The gas sensor of claim 1 wherein the plurality of perforations are each circular.
4 . The gas sensor of claim 1 further comprising a spring clip extending across the housing and positioned in contact with the spreader plate to hold the spreader plate in contact with the substrate.
5 . The gas sensor of claim 1 wherein the spreader plate includes an outer edge and wherein each of the plurality of perforations is positioned entirely within the outer edge.
6 . The gas sensor of claim 1 wherein the contact portion of the wick is positioned between the spreader plate and the substrate.
7 . The gas sensor of claim 1 wherein the spreader plate is formed from polycarbonate.
8 . The gas sensor of claim 1 wherein the spreader plate is positioned between the reservoir and the contact portion of the wick.
9 . An electrochemical gas sensor, comprising:
a housing having a reservoir for receiving an electrolyte;
an electrode assembly positioned within the housing and including at least a working electrode and a counter electrode;
a wick positioned within the housing and extending into the reservoir to contact the electrolyte, the wick being in contact with the working and counter electrodes; and
a spreader plate positioned within the housing and in contact with the wick to hold the wick in contact with the electrode assembly, wherein the spreader plate is a planar member having a plurality of perforations formed therein.
10 . The gas sensor of claim 9 wherein the spreader plate contacts the wick to define a generally planar contact portion of the wick, wherein the contact portion of the wick is adjacent the working and counter electrodes.
11 . The gas sensor of claim 10 further comprising a spring clip extending across the housing and positioned in contact with the spreader plate to hold the spreader plate in contact with the electrode assembly.
12 . The gas sensor of claim 9 wherein the plurality of perforations are each circular.
13 . The gas sensor of claim 9 wherein the spreader plate includes an outer edge and wherein each of the plurality of perforations is positioned entirely within the outer edge.
14 . The gas sensor of claim 10 wherein the contact portion of the wick is positioned between the spreader plate and the electrode assembly.
15 . The gas sensor of claim 9 wherein the spreader plate is formed from polycarbonate.
16 . The gas sensor of claim 9 wherein the spreader plate is positioned between the reservoir and the contact portion of the wick.