Apparatus for determining and/or monitoring at least one process variable

Patent metadata

Field	Value
Publication number	US-11255714-B2
Application number	US-201615747192-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Jul 30, 2015
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

An Apparatus for determining and/or monitoring at least one process variable of a medium in a container, comprising: a mechanically oscillatable unit a driving/receiving unit for exciting the mechanically oscillatable unit to execute mechanical oscillations by means of an electrical, exciting signal and for receiving and transducing the mechanical oscillations into an electrical, received signal a control unit, which is embodied to produce the exciter signal starting from the received signal and to set a predeterminable phase shift between the exciter signal and the received signal, an electromagnetically oscillatable unit, an active element for producing and/or maintaining electromagnetic oscillations in the electromagnetically oscillatable unit, which active element forms together with the electromagnetically oscillatable unit an oscillator, a coupling unit, which is embodied to tap an output signal from the active element, and an evaluation unit, which evaluation unit is embodied to determine the at least one process variable from the received signal and/or from the output signal.

First claim

The invention claimed is:

1. An apparatus for determining and/or monitoring at least one process variable of a medium in a container, comprising:
a mechanically oscillatable unit;
a driving/receiving unit for exciting said mechanically oscillatable unit to execute mechanical oscillations by means of an electrical, exciting signal and for receiving and transducing the mechanical oscillations into an electrical, received signal;
a control unit, which is embodied to produce the exciter signal starting from the received signal and to set a predeterminable phase shift between the exciter signal and the received signal;
an electromagnetically oscillatable unit;
an active element for producing and/or maintaining electromagnetic oscillations in said electromagnetically oscillatable unit, which active element forms together with said electromagnetically oscillatable unit an oscillator;
a coupling unit, which is embodied to tap an output signal from said active element; and
an evaluation unit, wherein:
said evaluation unit is embodied to determine the at least one process variable from the received signal and/or from the output signal; and
wherein said at least one mechanically oscillatable unit is in the form of an oscillatory fork having a first fork tine and a second fork tine, and said at least one electromagnetically oscillatable unit is provided with at least a first conductive trace and a second conductive trace.

2. The apparatus as claimed in claim 1 , wherein:
said mechanically oscillatable unit is a membrane, a single rod, or an oscillatory fork.

3. The apparatus as claimed in claim 1 , wherein:
said mechanically oscillatable unit is manufactured of a metal, a ceramic or a synthetic material.

4. The apparatus as claimed in claim 1 , wherein:
said driving/receiving unit includes at least one piezoelectric element or at least one coil.

5. The apparatus as claimed in claim 1 , wherein:
said electromagnetically oscillatable unit is embodied as a waveguide, especially as a coaxial cable, hollow conductor, or microstrip transmission line, as a patch antenna, as a dielectric gradient conductor or as a two-wire line.

6. The apparatus as claimed in claim 1 , wherein:
said at least one process variable is a fill level or limit-level of the medium in the container, the viscosity, the density, the permittivity, the permeability, the dielectric loss factor, the protein content and/or fat content of a medium, especially a food, or the water fraction in an oil.

7. The apparatus as claimed in claim 1 , wherein:
said electromagnetically oscillatable unit is arranged on at least one portion or within at least one portion of said mechanically oscillatable unit or together with, within, or as part of said driving/receiving unit.

8. The apparatus as claimed in claim 1 , wherein:
said first conductive trace of said at least one of the at least one electromagnetically oscillatable unit is at least partially arranged in the interior of said first fork tine and said second conductive trace of said electromagnetically oscillatable unit is at least partially arranged in the interior of said second fork tine of said at least one mechanical oscillatable unit.

9. The apparatus as claimed in claim 1 , wherein:
said first and said second conductive trace of at least one of said at least one electromagnetically oscillatable unit is arranged at least partially in the interior of the same fork tine of said at least one mechanical oscillatable unit.

10. The apparatus as claimed in claim 1 , wherein:
said first and/or said second conductive trace of said least one electromagnetically oscillatable unit are/is arranged within a housing of said driving/receiving unit.

11. The apparatus as claimed in claim 1 , wherein:
at least two electromagnetically oscillatable units are provided; and
said at least two electromagnetically oscillatable units are arranged and said at least one evaluation unit is embodied in such a manner to ascertain, from a comparison of at least a first output signal of said first electromagnetically oscillatable unit and a second output signal of said second electromagnetically oscillatable unit, presence of an accretion on said at least one mechanically oscillatable unit.

12. The apparatus as claimed in claim 1 , wherein:
at least one electromagnetically oscillatable unit is arranged in a housing of said driving/receiving unit; and
said evaluation unit is embodied to ascertain, from the output signal of said electromagnetically oscillatable unit, penetration of medium into said housing of said driving/receiving unit.

13. The apparatus as claimed in claim 1 , further comprising:
a temperature sensor for registering temperature of the medium is present.

14. The apparatus as claimed in claim 1 , wherein:
said electromagnetically oscillatable unit oscillates with a frequency in the range from 100 MHz to 100 GHz; and/or
said mechanically oscillatable unit oscillates with a frequency in the range from 100 Hz to 100 kHz.

15. The apparatus as claimed claim 1 , wherein:
a trigger unit is provided, which trigger unit is embodied to trigger at least the out-coupling of the output signal on a certain time interval ascertainable based on the exciting signal as a function of time, especially at a time interval having a zero crossing or an extreme-value of the exciter signal.

Assignees

• Endress Hauser Gmbh Co Kg
• Endress Hauser Se Co Kg

Inventors

• Blodt Thomas
• Brengartner Tobias
• Mack Benjamin
• Klofer Peter

Classifications

• G01N2009/006

  vibrating tube, tuning fork · CPC title

• G01N11/16

  by measuring damping effect upon oscillatory body · CPC title

• G01N9/002

  using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis (G01N9/34 takes precedence) · CPC title

• G01N33/2847

  Water in oils · CPC title

• G01N33/03

  Edible oils or edible fats · CPC title