Vibronic measuring device

Patent metadata

Field	Value
Publication number	US-9575035-B2
Application number	US-201113818855-A
Country	US
Kind code	B2
Filing date	Aug 9, 2011
Priority date	Sep 3, 2010
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A vibronic measuring device for determining at least one process variable of a medium. Included are: an oscillatable unit; a transmitting/receiving unit, which, by means of a transmission signal, excites the oscillatable unit to execute mechanical oscillations and receives the mechanical oscillations and converts such into an analog, electrical, received signal; and a control/evaluation unit (MC), which receives the analog, received signal, digitizes such and determines the process variable therefrom and which produces the transmission signal. Between the transmitting/receiving unit and the control/evaluation unit, a controllable amplifier is arranged, which receives the received signal and produces an adapted, received signal, and that the control/evaluation unit determines an amplitude of the received signal and, as a function of the determined amplitude, controls the amplifier in such a manner that the amplitude of the adapted, received signal is adapted to a digitizable voltage range predetermined by the control/evaluation unit.

First claim

The invention claimed is:

1. A vibronic measuring device for determining at least one process variable of a medium, comprising:
an oscillatable unit;
a transmitting/receiving unit, which, by means of a transmission signal, excites the oscillatable unit to execute mechanical oscillations and receives the mechanical oscillations and converts such into an analog, electrical, received signal; and
a control/evaluation unit, which is a microcontroller, wherein:
between said transmitting/receiving unit and said control/evaluation unit, a controllable amplifier is arranged, which receives the received signal and produces an adapted, received signal; and
said control/evaluation unit receives the adapted, received signal via an analog-digital converter forming the signal input of said control/evaluation unit, which analog-digital converter converts the adapted, received signal into a digital adapted received signal, said control/evaluation unit determines the process variable from the adapted received signal and produces the transmission signal, and said control/evaluation unit determines a current amplitude of the adapted received signal, and, as a function of the determined amplitude, controls said amplifier by adjusting the degree of amplification in such a manner that the amplitude of the adapted, received signal is adapted to a reference voltage of said analog-digital converter.

2. The measuring device as claimed in claim 1 , further comprising:
a filter element arranged between said controllable amplifier and said control/evaluation unit.

3. The measuring device as claimed in claim 1 , wherein:
said control/evaluation unit has a digital-analog converter, which supplies the transmission signal to said transmitting/receiving unit.

4. The measuring device as claimed in claim 3 , wherein:
between said digital-analog converter and said transmitting/receiving unit, an amplifier with fixedly set amplification factor is arranged, which amplifies the transmission signal.

5. The measuring device as claimed in claim 1 , wherein:
said control/evaluation unit controls the amplitude of the transmission signal as a function of the amplitude of the received signal in such a manner that the amplitude of the received signal is adaptable to the digitizable voltage range.

6. The measuring device as claimed in claim 5 , wherein:
a second controllable amplifier is arranged between a signal output of said control/evaluation unit for the transmission signal and said transmitting/receiving unit; and
said control/evaluation unit controls said second controllable amplifier as a function of the amplitude of the received signal in such a manner that the amplitude of the received signal is adaptable by said first amplifier to the digitizable voltage range.

7. The measuring device as claimed in claim 1 , wherein:
said oscillatable unit is one of:
an oscillatory fork, a membrane and a single rod.

8. The measuring device as claimed in claim 1 , wherein:
the process variable is one of: a predetermined fill level of the medium in a container and/or the density of the medium and/or the viscosity of the medium.

Assignees

• Urban Martin
• Brengartner Tobias
• Muller Alexander
• Endress Hauser Gmbh Co Kg

Inventors

• Urban Martin
• Brengartner Tobias
• Muller Alexander

Classifications

• B25F5/006

  Vibration damping means · CPC title

• G01N29/036

  by measuring frequency or resonance of acoustic waves · 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

• G01F23/2967

  for discrete levels · CPC title

• G01N29/022

  Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices (microdevices per se B81B) · CPC title