DE-102024003669-A1 - Sensor arrangement

Abstract

The invention relates to a sensor arrangement (S) with a number of electrodes (E1 to E3) arranged in a container (1) integrated in a liquid circuit for detecting a fill level (F) and/or an electrical conductivity of a liquid (2) circulating in the liquid circuit, wherein a first electrode (E1) and a second electrode (E2) are arranged in the container (1) as an electrode pair for measuring the electrical conductivity, and a third electrode (E3) is arranged in the container (1) for detecting sufficient filling of the container (1) with the liquid (2). According to the invention, it is provided that - the two electrodes forming the electrode pair (E1, E2) are made of a noble metal and/or of a metallic material coated with a noble metal and/or of a high-alloy chromium-nickel steel and/or of a chromium-nickel-molybdenum steel, - the third electrode (E3) is formed from an aluminum alloy of the 1xxx and 3xxx series, wherein - the electrodes (E1 to E3) are arranged at a predetermined distance ( d1 , d2 ) between 2 mm and 50 mm from each other in the container (1).

Inventors

• Arnd Bressel
• Diana Franz
• Benoit Remy

Assignees

• Mercedes-Benz Group AG

Dates

Publication Date

20260513

Application Date

20241108

Claims (3)

1. Sensor arrangement (S) with a number of electrodes (E1 to E3) arranged in a container (1) integrated in a liquid circuit for detecting a fill level (F) and/or an electrical conductivity of a liquid (2) circulating in the liquid circuit, wherein a first electrode (E1) and a second electrode (E2) are arranged in the container (1) as an electrode pair for measuring the electrical conductivity and a third electrode (E3) is arranged in the container (1) for detecting sufficient filling of the container (1) with the liquid (2), characterized in that - the two electrodes forming the electrode pair (E1, E2) are made of a noble metal and/or of a metallic material coated with a noble metal and/or of a high-alloy chromium-nickel steel and/or of a chromium-nickel-molybdenum steel, - the third electrode (E3) is made of an aluminum alloy of the 1xxx series and the 3xxx series, wherein - the electrodes (E1 to E3) are each arranged at a predetermined distance (d 1 , d 2 ) between 2 mm and 50 mm in the container (1).
2. Sensor arrangement (S) according to Claim 1 , characterized in that the first electrode (E1) and the third electrode (E3) are arranged at a predetermined distance (d 2 ) from each other and the second electrode (E2) and the third electrode (E3) are arranged at a predetermined distance (d 1 ) from each other.
3. Sensor arrangement (S) according to Claim 2 , characterized in that the electrodes (E1 to E3) are of equal length and are arranged parallel to each other and at the same height in the container (1).

Description

The invention relates to a sensor arrangement with a number of electrodes arranged in a container integrated in a liquid circuit for detecting a fill level and/or an electrical conductivity of a liquid circulating in the liquid circuit, wherein a first electrode and a second electrode are arranged in the container as an electrode pair for measuring the electrical conductivity and a third electrode is arranged in the container for detecting sufficient filling of the container with the liquid. From the DE 10 2023 005 012 A1 A level sensor arrangement is known. The level sensor arrangement comprises a number of electrodes arranged in a container integrated into a liquid circuit for detecting the level and electrical conductivity of a liquid circulating in the liquid circuit. Two electrodes are arranged in the container as an electrode pair for measuring the electrical conductivity by detecting the DC resistance and electrical impedance of the liquid located between the electrodes. The electrode pair is configured to perform an electrical continuity measurement to determine the liquid level in the container and a capacitive method to measure the permittivity of the liquid. The invention is based on the objective of specifying a sensor arrangement. The problem is solved according to the invention by a sensor arrangement which has the features specified in claim 1. Advantageous embodiments of the invention are the subject of the dependent claims. A sensor arrangement comprises a number of electrodes arranged in a container integrated into a liquid circuit for detecting the fill level and/or electrical conductivity of a liquid circulating in the liquid circuit, wherein a first electrode and a second electrode are arranged in the container as an electrode pair for measuring the electrical conductivity, and a third electrode is arranged in the container for detecting sufficient filling of the container with the liquid. According to the invention, it is provided that - the two electrodes forming the electrode pair are made of a noble metal and/or of a metallic material coated with a noble metal and/or of a high-alloy chromium-nickel steel and/or of a chromium-nickel-molybdenum steel, - the third electrode is formed from an aluminum alloy of the 1xxx and 3xxx series, wherein - the electrodes are arranged at a predetermined distance between 2 mm and 50 mm from each other in the container. The sensor arrangement can be used to monitor corrosion protection in the cooling circuit of a vehicle, particularly an electrified vehicle, such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle. Specifically, the corrosion protection is monitored by means of the third electrode, which in one possible configuration is positioned between the first and second electrodes. Due to this design, the first and second electrodes are therefore not exposed to any direct chemical change of a material surface through contact with the liquid, in particular a coolant circulating in the cooling circuit, but their electrochemical behavior can only be influenced by the formation of at least one surface layer, for example by deposition of corrosion products. In particular, the third electrode is made of particularly corrosion-sensitive materials of the AW-3xxx series, for example AlSi9Cu3, which have particularly high requirements for an inhibiting effect of the liquid, especially a coolant. In particular, it is possible to arrange and use the sensor assembly in an existing installation space with an existing cable set. Exemplary embodiments of the invention are explained in more detail below with reference to drawings. This shows: 1 schematically a sensor arrangement and 2 Schematic representation of the sensor arrangement in a container of a liquid circuit. Corresponding parts are marked with the same reference symbols in all figures. 1 shows a sensor arrangement S and 2 shows the sensor arrangement S arranged in a container 1, in particular in an expansion tank, of a liquid circuit according to 1 . It is generally known that a water-glycol mixture typically circulates as the fluid 2, particularly as the operating medium, i.e., the coolant, in the cooling circuit of a vehicle's cooling system. Such a fluid 2 exhibits ionic conductivity due to the addition of salt-like inhibitors, which can lead to an electric current flow within the fluid 2 upon contact with electrical components under increased voltage. Therefore, for electric vehicles, hybrid vehicles, or fuel cell vehicles, the use of low- to non-electrically conductive fluids 2, i.e., oil- or glycol-water-based coolants, is being investigated to reduce electrical hazards in the event of component failure and to enable direct cooling of electrical components without complex insulation measures. If such a low-conductivity fluid 2 is used as the coolant, it is necessary to reduce the amount of corrosion inhibitors contained in the coolant, i.e., the fluid 2, compared to currently avai