Electroanalytical transducers
First Claim
1. A method for preventing contact by an electrolyte of selected portions of an electrode not intended to be contacted by the electrolyte in an amperometric electroanalytical transducer comprising contacting at least a part of the surface of said electrode portions with an insulator adapted to seal said selected portions of said electrode against contact with said electrolyte, maintaining the insulator and the electrode in mutually pressing engagement at a pressure of greater than about 0.1 kg/mm2 at the interface thereof.
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Accused Products
Abstract
Electroanalytic transducers for electrochemical analysis of chemical substances are disclosed. The transducers are of the type which include electrodes contacting an electrolyte solution. In accordance with the method and apparatus of the invention, means insulating an electrode are held in a mutually pressing engagement over preselected portions of the electrode to insulate that portion from the electrolyte and prevent creep of the electrolyte between the insulating means and the preselected portions. Thus, the surface area of the electrode exposed to the electrolyte is maintained substantially constant during the service life of the transducer. In a preferred embodiment, sensor or working and counter electrodes are coaxially mounted and circumferentially coaxially separated by annular insulating means. Spring means urge the inner coaxially mounted electrode and the annular insulating means together so that only the surface of the cross-sectional end of the inner electrode is exposed to electrolyte. Thus, a working or sensing surface area of the electrode exposed to electrolyte may be maintained substantially constant during service.
20 Citations
39 Claims
- 1. A method for preventing contact by an electrolyte of selected portions of an electrode not intended to be contacted by the electrolyte in an amperometric electroanalytical transducer comprising contacting at least a part of the surface of said electrode portions with an insulator adapted to seal said selected portions of said electrode against contact with said electrolyte, maintaining the insulator and the electrode in mutually pressing engagement at a pressure of greater than about 0.1 kg/mm2 at the interface thereof.
- 13. In an amperometric electroanalytical transducer comprising an electrode and an insulator for preventing contact by an electrolyte of selected portions of the electrode, the improvement comprising means for maintaining surface portions of an insulator and at least part of the surface of said selected portions of the electrode in mutually pressing engagement at a pressure of greater than about 0.1 kg/mm2 at the interface thereof.
- 25. An amperometric electroanalytical transducer comprising insulating means including an insulator, at least one electrode having an electroanalytically effective surface portion for contact with an electrolyte, said surface portion being limited by said insulator, and means for pressingly engaging said insulator and said electrode at a pressure of greater than about 0.1 kg/mm2 at the interface of said insulator and electrode for counteracting electrolyte penetration into said interface.
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36. An amperometric cell for the quantitative determination of the concentration of a component in a fluid comprising an electroanalytical transducer comprising insulating means including an insulator, at least one electrode having an electroanalytically effective surface portion for contact with an electrolyte, said surface portion being limited by said insulator, and means for pressingly engaging said insulator and said electrode at the interface of the electrode and insulator at a pressure of greater than about 0.1 kg/mm2 for counteracting electrolyte penetration into said interface between said insulator and said electrode,
said cell comprising an electrolyte receiving container portion, a working electrode, a counter electrode and an insulator in contact with said working electrode, said insulating means including a solid creep-resistant material and said insulator contacting said working electrode at a predetermined and substantially constant pressure so as to limit and counteract entry of electrolyte into the interface between said working electrode and said insulator when said cell is operated.
- 38. An electroanalytical transducer comprising an electrolyte, a chamber portion for receiving said electrolyte, a first electrode arranged substantially at the center of the radial cross-section of said chamber portion and having an electroanalytically effective surface portion for contact with the electrolyte, insulating means including an insulator in a generally coaxial arrangement around said first electrode and a second electrode in a generally coaxial arrangement around said insulator and having a recessed part, a member capable of being displaced in a generally axial direction within the recessed part of said second electrode, and a spring operationally connected with said displaceable member, said first electrode and said insulator each having a contact face for a mutually sealing engagement, said displaceable member forcing said spring means against said first electrode for pressingly engaging said first electrode and said insulator and maintaining sealingly effective pressure between said first electrode and said insulator in at least a portion of said interface.
Specification