US 11,774,477 B2
Measuring device for determining a dielectric constant comprising an electrically conductive arrangement electrically contacts two waveguides with one another
Thomas Blödt, Steinen (DE)
Assigned to Endress+Hauser SE+Co. KG, Maulburg (DE)
Appl. No. 17/635,040
Filed by Endress+Hauser SE+Co. KG, Maulburg (DE)
PCT Filed Jul. 10, 2020, PCT No. PCT/EP2020/069522
§ 371(c)(1), (2) Date Feb. 14, 2022,
PCT Pub. No. WO2021/028130, PCT Pub. Date Feb. 18, 2021.
Claims priority of application No. 10 2019 121 995.7 (DE), filed on Aug. 15, 2019.
Prior Publication US 2022/0283210 A1, Sep. 8, 2022
Int. Cl. G01F 23/292 (2006.01); G01R 27/26 (2006.01)
CPC G01R 27/2682 (2013.01) [G01F 23/292 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A measuring device for determining a dielectric value of a medium, comprising:
a signal production unit designed to produce an electrical, high frequency signal having a frequency varying within a frequency band;
a first waveguide having an in-coupling element designed to couple the produced high frequency signal into the first waveguide, a first end region designed for reflecting the high frequency signal, and a first signal gate arranged lying opposite the first end region via which the high frequency signal can be out-coupled into the medium;
a second waveguide having a second end region is designed for reflecting the high frequency signal, a second signal gate arranged lying opposite the second end region and arranged lying opposite the first signal gate such that the high frequency signal is in-coupleable into the second waveguide via the second signal gate after passage through the medium, and an out-coupling element designed to out-couple the high frequency signal from the second waveguide;
an electrically conductive arrangement that electrically contacts the two waveguides with one another; and
a signal evaluation unit connected at least to the out-coupling element, wherein the signal evaluation unit is configured:
to receive within the frequency band a frequency-dependent, reflected fraction of the high frequency signal in-coupled into the first waveguide and/or a frequency-dependent, transmitted fraction of the high frequency signal in-coupled into the first waveguide,
to ascertain, based on the reflected fraction, a frequency-dependent, reflection minimum and a corresponding frequency, and/or to ascertain, based on the transmitted fraction, a frequency-dependent, transmitted maximum and a corresponding frequency,
to determine, based on the corresponding frequency of the reflection minimum or based on the corresponding frequency of the transmitted maximum, a real part of the dielectric value,
to determine, based on the transmitted fraction at the corresponding frequency of the reflection minimum, an imaginary part of the dielectric value, and
to determine, based on the imaginary part of the dielectric value and the real part of the dielectric value, a magnitude of the dielectric value.