Plasma oxygen permeability meter
OwnerLouis W. Morganinventor
Life of this patent
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Abstract
A polarographic oxygen detection cell of the type having concentric coplanar electrodes. The cell achieves more consistent and predictable operation by using electrode insulators to prevent electrochemical reaction between the areas of high charge density on the cathode and anode conduction disk and those portions of the electrolyte in which increased ion concentration has been attracted by this high charge density, and using the OH.sup.- based electrolyte and a carbon anode so that the reaction at the anode produces gas which can be bled off to avoid altering the composition of the anode or electrolyte.
Claims14
A polarographic cell having substantially uniform electrochemical reactivity on a relatively large planar area, comprising:
- a. an electrical conductor with a planar surface, and
- b. means to compensate for the effect on an electrolyte of unequal distribution of electrostatic charge on said surface by preventing electron transfer across the boundary between said surface and said electrolyte wherever said electrostatic charge on said surface has high enough density to substantially alter the ion concentrations at said boundary, such as to ensure that electrons move across said boundary only where said electrostatic charge has low enough density to permit said ion concentrations at said boundary to be substantially uniform,
- whereby electrochemical reactions take place in said cell with substantial uniformity as described by the Nernst equation for said substantially uniform ion concentrations.
In a polarographic cell for measuring oxygen permeation through fluid samples held in a sample well, said cell being of the type having generally coplanar sensing and counter electrodes in contact with a common electrolyte, said sensing electrode being a flat circular cathode with a relatively large area surface for quantitatively reducing oxygen, said counter electrode being an annular disk anode substantially concentric to said cathode, the improvements comprising:
- a. means for suppressing an electrical current which would pass through said electrolyte from said cathode to said anode in the absence of oxygen entering said cell through said sample well, and
- b. means for minimizing the accumulation of reaction products within said cell.
Dependencies are inferred from the claim text.