# US 11,079,349 B2 · Electrical measuring assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,349 B2 - Document ID: US11079349B2 - Status: Granted - Kind: B2 - Application number: 16/605,381 - Filed: 2018-03-19 - Published: 2021-04-29 - Granted: 2021-08-03 - Earliest claimed: 2017-04-28 - Assignees: Testo SE & Co. KGaA - Applicants: Testo SE & Co. KGaA - Inventors: Siegfried Stallmann; Oliver Wiech - Web page: https://patentgrep.com/patent/US11079349B2 ## CPC - G01N 27/226: {Construction of measuring vessels; Electrodes therefor} - A47J 36/02: Selection of specific materials, e.g. heavy bottoms with copper inlay or with insulating inlay - G01N 27/22: by investigating capacitance - G01N 27/221: {by investigating the dielectric properties (using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26)} - G01N 33/03: Edible oils or edible fats - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A47J: KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES ## Abstract In an electrical measuring assembly (1), in which an inner electrode (2) and an outer electrode (3), which form a measuring chamber (4) therebetween for a capacitive examination of a liquid flowing past, are formed from a food-safe stainless steel, the inner electrode (2) is supported at the axial ends (6, 7) thereof on the outer electrode (3) by insulating elements (10, 11), which are produced from a ceramic material or plastic material that can be machined and/or that has a permittivity that is temperature-independent in a working range and/or that is free of pores and/or does not absorb water. ## Claims ### Claim 1 An electrical measuring assembly (1) for capacitive measurement of a liquid, the electrical measuring assembly comprising: an outer electrode (3), an inner electrode (2) arranged concentrically to the outer electrode (3), such that the outer electrode encloses the inner electrode forming a measuring chamber (4) between the inner electrode (2) and the outer electrode (3), the inner electrode (2) is secured to the outer electrode (3) at axial ends of the measuring chamber (4), at least one inlet opening (8) to the measuring chamber (4) and at least one discharge opening (9) from the measuring chamber (4) are provided in the outer electrode (3), the outer electrode (3) and the inner electrode (2) are formed of stainless steel, and insulating elements (10, 11) that retain the inner electrode (2) at the axial ends (6, 7), the insulating elements (10, 11) are formed of a food-safe material, comprising a glass ceramic or a plastic, that is at least one of a) a material having a permittivity that, over a temperature range from 20° C. to 200° C., varies by a maximum of 30%, b) a pore-free material, c) a material which absorbs no water, or d) a chip-machineable material. ### Claim 2 (depends on 1) The electrical measuring assembly (1) as claimed in claim 1, wherein the stainless steel is food-safe, and comprises at least one of material number 1.4404, AISI 316L, or X2CrNiMo17-12-2. ### Claim 3 (depends on 1) The electrical measuring assembly (1) as claimed in claim 1, wherein the insulating elements (10, 11) comprise a glass matrix, with glimmer crystals, including 55% fluorophlogopite glimmer and/or 45% borosilicate glass, wherein a chemical composition of 46% silicon oxide, 17% magnesium oxide, 16% aluminum oxide, 10% potassium oxide, 7% boron oxide and 4% fluorine. ### Claim 4 (depends on 1) The electrical measuring assembly (1) as claimed in claim 1, wherein the insulating elements (10, 11) are turned parts. ### Claim 5 (depends on 1) The electrical measuring assembly (1) as claimed in claim 1, further comprising at least one seal (13) of a food-safe sealing material arranged between the inner electrode (2) and at least one of the insulating elements (10, 11), or between at least one of the insulating elements (10, 11) and the outer electrode (3), or both. ### Claim 6 (depends on 1) The electrical measuring assembly as claimed in claim 1, wherein the outer electrode (3), on an outer side thereof, incorporates at least one material retraction (14), at least one of adjacent to at least one of the inlet opening (8) or the discharge opening (9) or over a length of the measuring chamber (4). ### Claim 7 An electrical measuring assembly (1) for capacitive measurement of a liquid, the electrical measuring assembly comprising: an outer electrode (3), an inner electrode (2) arranged concentrically to the outer electrode (3), such that the outer electrode encloses the inner electrode forming a measuring chamber (4) between the inner electrode (2) and the outer electrode (3), the inner electrode (2) is secured to the outer electrode (3) at axial ends of the measuring chamber (4), at least one inlet opening (8) to the measuring chamber (4) and at least one discharge opening (9) from the measuring chamber (4) are provided in the outer electrode (3), the inlet opening (8) and the discharge opening (9) are respectively configured as radially open, and an internal clearance (19) of the inlet opening (8) and the discharge opening (9), transversely to a longitudinal direction (17), is smaller than an internal diameter (20) of the measuring chamber (4). ### Claim 8 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein the inlet opening (8) and the discharge opening (9) are respectively configured as a radially open longitudinal slot (16), respectively oriented in a longitudinal direction (17) of the outer electrode (3), and the internal clearance (19) comprises a slot width, or at least one of the inlet opening (8) or the discharge opening (9) is configured as at least one bore. ### Claim 9 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein at least one of the inlet opening (8) or the discharge opening (9) extends over at least half of a length of the measuring chamber (4). ### Claim 10 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein the inlet opening (8) and the discharge opening (9) are arranged on mutually opposing sides (22, 23) of the outer electrode (3), and the inner electrode (2) is arranged between the inlet opening (8) and the discharge opening (9). ### Claim 11 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein the measuring chamber (4) defines a measuring gap (24), having a gap width (25), on either side of the inner electrode (2), and a sum of the gap widths (25) is smaller than the internal clearance (19) of at least one of the inlet opening (8) or of the discharge opening (9). ### Claim 12 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein the inner electrode (2) overlaps at least one of the inlet opening (8) or the discharge opening (9) on an inner side, in a circumferential direction. ### Claim 13 (depends on 11) The electrical measuring assembly (1) as claimed in claim 11, wherein at least one of one of the inlet opening (8) or the discharge opening (9) comprises a channel (27), a channel length (28) of which is greater than the gap width (25) of the measuring gap (24) between the outer electrode (3) and the inner electrode (2). ### Claim 14 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, wherein the measuring chamber (4) has a hollow cylinder shape. ### Claim 15 (depends on 7) The electrical measuring assembly as claimed in claim 7, wherein the outer electrode (3) is arranged in an encapsulated housing (29). ### Claim 16 (depends on 15) The electrical measuring assembly (1) as claimed in claim 15, wherein the housing incorporates an inlet connection (30) corresponding to the inlet opening (8), and a discharge connection (31) corresponding to the discharge opening (9), and the inlet connection (30) and the discharge connection (31) are arranged with a mutual offset in the longitudinal direction. ### Claim 17 (depends on 16) The electrical measuring assembly (1) as claimed in claim 16, wherein the inlet opening (8), in the longitudinal direction (17), extends no further than a region which is encompassed by the inlet connection (30) or the discharge opening (9), in the longitudinal direction (17), extends no further than a region which is encompassed by the discharge connection (30), or both. ### Claim 18 (depends on 16) The electrical measuring assembly (1) as claimed in claim 16, wherein the outer electrode (3) is arranged with a clearance to the housing, and at least one of an exterior flow baffle (32) is configured on the outer electrode (3) or at least one recess (35) is configured on the outer electrode for a temperature sensor (34). ### Claim 19 (depends on 7) The electrical measuring assembly (1) as claimed in claim 7, further comprising: the outer electrode (3) and the inner electrode (2) are formed of stainless steel, and insulating elements (10, 11) that retain the inner electrode (2) at the axial ends (6, 7), the insulating elements (10, 11) are formed of a food-safe material, comprising a glass ceramic or a plastic, that is at least one of a) a material having a permittivity that, over a temperature range from 20° C. to 200° C., varies by a maximum of 30%, b) a pore-free material, c) a material which absorbs no water, or d) a chip-machineable material.