Reference electrode
AssigneeMettler-Toledo AG
InventorRolf Thrier
Life of this patent
Estimating the term…
Abstract
A reference electrode with an in-situ modified porous diaphragm has at least one housing (1, 201, 301), a first conductor element (4, 204, 304), a modifying electrolyte which is capable of free-flow movement and is contained in the housing (1, 201, 301), and a porous diaphragm (3, 203, 303) which establishes a liquid connection between the modifying electrolyte and a measurement medium (9, 209, 309). The modifying electrolyte seeps out through the porous diaphragm during operation. The modifying electrolyte has a first component and a surface-modifying component which modifies the surface of the porous diaphragm (3, 203, 303) in situ during the passage of the modifying electrolyte. A method for modifying the porous diaphragm in situ is presented.
Claims14
A method for the in-situ modification of a porous diaphragm which is arranged in a reference electrode as a liquid connection to a measurement medium, the reference electrode comprising at least one housing, a first conductor element, a modifying electrolyte, comprising a first component and arranged in one of the at least one housings as a free-flowing liquid, and the porous diaphragm, which establishes a liquid connection between the housing containing the modifying electrolyte and the measurement medium and through which the modifying electrolyte seeps out during operation, and a reference electrolyte, contained in a reference housing that has a further porous diaphragm, the first conductor element being immersed in the reference electrolyte, which is in contact with the modifying electrolyte, which serves as a bridge electrolyte by way of the further porous diaphragm, wherein the method comprises the steps of:
- adding a surface-modifying component to the modifying electrolyte that is arranged in the reference electrode, wherein the surface-modifying component modifies a surface of the porous diaphragm in situ during the passage of the modifying electrolyte, and
- ensuring the outward migration of the modifying electrolyte through the porous diaphragm.
A reference electrode for contact with a measurement medium, comprising:
- at least one housing;
- a first conductor element;
- a modifying electrolyte, comprising a first component and a surface-modifying component, the modifying electrolyte being a free-flowing liquid that is arranged in one of the at least one housings to provide a bridge electrolyte;
- and
- a porous diaphragm which establishes a liquid connection between the housing containing the modifying electrolyte and the measurement medium and through which the modifying electrolyte seeps out during operation, wherein the surface-modifying component modifies the surface of the porous diaphragm in situ during the passage of the modifying electrolyte;
- and a reference electrolyte, contained in a reference housing that has a further porous diaphragm, the first conductor element being immersed in the reference electrolyte, which is in contact with the modifying electrolyte, which serves as a bridge electrolyte by way of the further porous diaphragm.
The reference electrode according to 9, characterized in that the surface-modifying component is selected from the group consisting of:
- lactic acid, citric acid, malic acid, tartaric acid, ascorbic acid, salts of said acids, and mixtures thereof.
Dependencies are inferred from the claim text.