CLOSURE DEVICE FOR A MEASURING CHAMBER OF AN ELECTROCHEMICAL SENSOR

Abstract

A closure device for a measuring chamber of an electrochemical sensor, a measuring chamber comprising such a closure device, and an electrochemical sensor comprising such a measuring chamber.

Claims

1-14. (canceled)

15. A closure device for a measuring chamber of an electrochemical sensor for determining a constituent in a sample, the closure device having a membrane with a permeable surface section so that the membrane allows a substance to be supplied to and/or discharged from the measuring chamber, wherein the closure device comprises a masking element which at least partially closes the permeable surface section of the membrane so that the supply and/or discharge of the substance to and/or from the measuring chamber is partially blocked or at least inhibited.

16. The closure device according to claim 15, wherein the masking element closes ?70%, preferably ?90%, of the permeable surface section.

17. The closure device according to claim 15, wherein the masking element is a foil with openings preferably created by punching or laser cutting.

18. The closure device according to claim 15, wherein the masking element is connected to the membrane in a force-fit, form-fit or material-fit manner, preferably in a force-fit manner.

19. The closure device according to claim 15, wherein the membrane comprises or consists of a polymer material.

20. The closure device according to claim 19, wherein the polymer material is polyethylene terephthalate (PET) or polycarbonate (PC).

21. The closure device according to claim 15, wherein the membrane is track-etched or sponge-like.

22. The closure device according to claim 15, wherein the closure device is configured and adapted such that in its operating position closing the measuring chamber, the masking element is arranged between the membrane and the measuring chamber.

23. The closure device according to claim 15, wherein the closure device is configured and adapted such that, in its operating position closing the measuring chamber, the membrane is arranged between the masking element and the measuring chamber.

24. A measuring chamber for an electrochemical sensor comprising a closure device according to claim 15.

25. An electrochemical sensor comprising a measuring chamber according to claim 24, wherein the electrochemical sensor is preferably a chlorine sensor.

26. he electrochemical sensor according to claim 25, wherein said electrochemical sensor is a chlorine sensor, preferably a total chlorine sensor.

27. A measuring device for determining a constituent of a sample comprising an electrochemical sensor according to claim 25.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0053] The appended figures represent specific embodiments of the invention, thereby show

[0054] FIG. 1: Schematic side view of a special embodiment of an inventive measuring chamber with selectively permeable membrane.

[0055] FIG. 2: Schematic top view of a special embodiment of an inventive measuring chamber with selectively permeable membrane.

DETAILED DESCRIPTION

[0056] FIGS. 1 and 2 show a schematic representation of a measuring chamber 4 of an electrochemical sensor according to the invention, which is covered by a closure device 1 according to the invention. The closure device comprises a selectively permeable membrane 3 and a masking element 7 arranged thereon in the direction of the measuring chamber. The electrode body of the measuring chamber has a working electrode 2 and an associated reference electrode 6. The face side of the working electrode 2 is surrounded by electrolyte 5, which is in contact with the sample via the membrane. The working and reference electrodes are connected to each other via a measuring device (not shown), so that during a measuring interval an electrical signal can be determined from which the presence of a constituent in a sample can be inferred. The electrode body is connected to the electronics (not shown) and immerses with the two electrodes in the electrolyte of the measuring chamber 4. Salt of a certain concentration is dissolved in the electrolyte 5. The housing of the measuring chamber is screwed to the closure device. This forms an electrolyte space 8 arranged between the working electrode and the membrane, which has a higher concentration of salt (than in an arrangement without masking element 7) and in the present case has a rectangular, linear shape.

[0057] The substance selectively permeable section of the membrane 3, which covers the measuring chamber 4, has a section which is not covered by the masking element 7. This is preferably equal to or smaller than the face side of the working electrode 2 and is arranged so that at least 80% of its projection onto the base area of the working electrode 2 is on the base area of the working electrode.

REFERENCE SIGNS

[0058] 1 Closure device [0059] 2 Working electrode [0060] 3 Membrane [0061] 4 Measuring chamber [0062] 5 Electrolyte in measuring chamber [0063] 6 Reference electrode [0064] 7 Masking element [0065] 8 Electrolyte space in closure device