Fill level measuring device

Patent metadata

Field	Value
Publication number	US-9523598-B2
Application number	US-201314369726-A
Country	US
Kind code	B2
Filing date	Jan 25, 2013
Priority date	Jan 27, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

Fill level measuring device having a control unit, which contains a high-frequency generator for generating a transmission signal, an amplifier, an amplifier and an evaluation unit, and a spatially remote probe, which contains a measuring impedance, a reference impedance, a first rectifier and a second rectifier, as well as a connecting line between the control unit and the probe, wherein the rectifier detects the voltage of the transmission signal in the probe, and this voltage is transmitted to the control unit as a first DC voltage signal, and the rectifier converts the probe current in the probe into a second DC voltage signal via measuring resistors, and both signals are supplied to the control unit for the purpose of determining the fill level, wherein the rectifiers are thermally coupled to one another.

First claim

The invention claimed is:

1. A fill level measurement device to determine a fill level of a medium in a container comprising: a control unit, a spatially separated probe and a multicore connection line configured to connect the control unit with the spatially separated probe, wherein the control unit contains a high frequency generator configured to generate a transmission signal, an evaluation unit configured to evaluate by means of a first amplifier and a second amplifier amplified probe signals, wherein the spatially separated probe contains a measuring impedance, not from the medium influencable reference impedance for calibration and temperature compensation, a first rectifier and a second rectifier, wherein the multicore connection line is configured to apply to the spatially separated probe the transmission signal and further configured to transmit the probe signals to the control unit, wherein the first amplifier and the second amplifier are connected on the output side to the evaluation unit and are configured to amplify direct voltages transmitted via the multicore connection line to the control unit, wherein the first rectifier is configured to acquire a voltage of the transmission signal in the spatially separated probe; the first rectifier, in combination with capacitors and resistors, is configured to transmit a first direct voltage signal via the multicore connection line to the control unit, wherein the second rectifier breaks the probe current down into its two half-waves so that a first of the two half-waves is present across a first measurement resistor and a second of the two half-waves is present across a second measurement resistor, wherein a second direct voltage, transmitted by the second rectifier in combination with capacitors and resistors, is supplied via the multicore connection line to the control unit, wherein the first rectifier and the second rectifier are thermally coupled with each other.

2. The fill level measurement device of claim 1 , wherein the high frequency generator operates in a frequency range between 50 MHz and 200 MHz.

3. The fill level measurement device of claim 1 , wherein the two measurement resistors share a common connection.

Assignees

• Ifm Electronic Gmbh

Inventors

• Hoch Werner

Classifications

• G01F23/266

  measuring circuits therefor · CPC title

• G01F25/00

  Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume · CPC title

• G01F23/265 Primary

  for discrete levels · CPC title

• G01F23/0084 Primary

  Physics · mapped topic

• G01F23/806 Primary

  Particular electronic circuits for handling non-digital processing equipment · CPC title