US 12,326,354 B2
Capacitive filling level probe without dead zone
Stefan Gebhardt, Lampertheim (DE); Armin Kohler, Lampertheim (DE); Eduard Bischler, Lampertheim (DE); and Nikita Philip Tatsch, Lampertheim (DE)
Assigned to RECHNER Industrie-Elektronik GmbH, Lampertheim (DE)
Filed by RECHNER Industrie-Elektronik GmbH, Lampertheim (DE)
Filed on Aug. 8, 2022, as Appl. No. 17/882,954.
Claims priority of application No. 21190413 (EP), filed on Aug. 9, 2021.
Prior Publication US 2023/0042239 A1, Feb. 9, 2023
Int. Cl. G01F 23/263 (2022.01); G01N 35/10 (2006.01)
CPC G01F 23/265 (2013.01) [G01N 35/1009 (2013.01); G01N 2035/1025 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A filling level measuring device for capacitive filling level measurement of filling material in the form of liquids and/or bulk materials in a container that has a counter electrode integrated in the container, comprising:
measuring electronics and a filling level probe connectable to the measuring electronics;
wherein the filling level probe includes a first electrode and a second electrode which have to be introduced into the container for the filling level measurement and which, in their introduced state, extend into the container one after the other in alignment along their longitudinal extension and spaced apart from each other and substantially parallel to the counter electrode; so that:
when the container is being filled, the first electrode will first be covered by filling material before the second electrode is at least partially covered by filling material, and a measurement section is defined by the entire range between a first end of the first electrode remote from the second electrode and a second end of the second electrode remote from the first electrode;
wherein the measuring electronics are configured to provide a measurement potential, a shielding potential, and a counter electrode potential, and comprise a switching unit including a first switch that is electrically connectable to the first electrode and a second switch that is electrically connectable to the second electrode;
wherein, for operating the filling level measuring device, the switching unit is operable to set a first, second, or third measurement mode, by having the first switch adapted to switch over between the measurement potential or the shielding potential that are configured to be applied to the first electrode, and by having the second switch adapted to switch over between the measurement potential or the shielding potential that are configured to be applied to the second electrode, and wherein in the first measurement mode the measurement potential is applied to the first electrode and the shielding potential to the second electrode, in the second measurement mode the shielding potential is applied to the first electrode and the measurement potential to the second electrode, and in the third measurement mode the measurement potential is applied to the first and second electrodes, and in each of the three measurement modes the counter electrode potential is applied to the counter electrode; and
wherein the measuring electronics comprise an evaluation unit that is electrically connected to the switching unit and adapted to control the switching unit and to calculate the filling level on the basis of relative changes in capacitance compared to a completely empty container as measured by the measurement electronics in each of the three measurement modes.