Method for the contactless determination of an electrical potential of an object using two different values for the electric flux, and device

Patent metadata

Field	Value
Publication number	US-9562930-B2
Application number	US-201114111640-A
Country	US
Kind code	B2
Filing date	Apr 14, 2011
Priority date	Apr 14, 2011
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

A method for the contactless determination of an electrical potential of an object, involves providing an electrode which is spatially at a distance from the object, connecting the electrode to a reference potential, determining a first temporal change in an electrical state of charge of the electrode at a first value for the electric flux between the electrode and the object, determining a second temporal change in the electrical state of charge of the electrode at a second value for the electric flux between the electrode and the object, and determining the electrical potential of the object at least from the first temporal change in the electrical state of charge and the second temporal change in the electrical state of charge and from a difference between the first value and the second value for the electric flux.

First claim

The invention claimed is:

1. A method for contactless determination of an electrical potential of an object, comprising:
providing a space between both a first electrode and a second electrode and the object;
comparing the first electrode to a first reference potential and the second electrode to a second reference potential;
setting a first value for electric flux between the first electrode and the object by positioning the first electrode at a first distance from the object and setting the first reference potential to a first potential value;
determining a first temporal change in an electrical state of charge of the first electrode at the first value for the electric flux between the first electrode and the object;
setting a second value for the electric flux between the second electrode and the object by positioning the second electrode at a second distance from the object and setting the second reference potential to a second potential value;
determining a second temporal change in the electrical state of charge of the second electrode at the second value for the electric flux between the second electrode and the object; and
determining the electrical potential of the object at least from the first temporal change in the electrical state of charge of the first electrode, from the second temporal change in the electrical state of charge of the second electrode and from a difference between the first value and the second value for the electric flux.

2. The method as claimed in claim 1 , wherein the first and second temporal changes in the electrical state of charge of the first and second electrodes are determined by measuring respective charge reversal currents.

3. The method as claimed in claim 1 , wherein
the first electrode is electrically connected to a first input of a first amplifier,
the first reference potential is electrically connected to a second input of the first amplifier,
an output of the first amplifier is electrically connected to the first input,
the second electrode is electrically connected to an output of a second amplifier, and
the second reference potential is electrically connected to an input of the second amplifier.

4. The method as claimed in claim 3 , wherein the output of the first amplifier is electrically connected to the first input of the first amplifier via a first resistive element, and the output of the second amplifier is electrically connected to the second electrode via a second resistor.

5. The method as claimed in claim 1 , wherein
the electrical potential of the object is a temporally variable electrical potential, and
the temporally variable electrical potential is determined.

6. The method as claimed in claim 1 , wherein
the electrical potential of the object is an alternating electrical potential, and
the alternating electrical potential is determined.

7. The method as claimed in claim 1 , wherein
at least one rotating impeller is arranged between the first electrode and the object and/or the second electrode and the object, and
a temporally constant electrical potential is determined.

8. The method as claimed in claim 1 , wherein the first distance is equal to the second distance, and the first potential value is different from the second potential value.

9. A device for the contactless determination of an electrical potential of an object, comprising:
a first electrode and a second electrode, both of which can be spatially arranged at distance from the object;
a first potential generator electrically compared to the first electrode to:
generate a first potential value to hereby set a first value for electric flux between the first electrode and the object when the first electrode is positioned at a first distance from the object; and
generate a second potential value which is different from the first potential value to thereby set a second value for the electric flux between the first electrode and the object when the first electrode is positioned at the first distance from the object; and a first evaluation unit to:
determine a first temporal change in an electrical state of charge of the first electrode at the first value for the electric flux between the first electrode and the object;
determine a second temporal change in an electrical state of charge of the first electrode at the second value for the electric flux between the first electrode and the object;
determine the electrical potential of the object at least from the first temporal change in the electrical state of charge of the first electrode, from the second temporal change in the electrical state of charge of the first electrode, and from a difference between the first value and the second value for the electric flux between the first electrode and the object; and
a second potential generator electrically compared to the second electrode to:
generate a first potential value to hereby set a first value for electric flux between the second electrode and the object when the second electrode is positioned at a second distance from the object; and
generate a second potential value which is different from the first potential value to thereby set a second value for the electric flux between the second electrode and the object when the second electrode is positioned at the second distance from the object; and a second evaluation unit to:
determine a first temporal change in an electrical state of charge of the second electrode at the first value for the electric flux between the second electrode and the object;
determine a second temporal change in an electrical state of charge of the second electrode at the second value for the electric flux between the second electrode and the object; and
determine the electrical potential of the object at least from the first temporal change in the electrical state of charge of the second electrode, from the second temporal change in the electrical state of charge of the second electrode, and from a difference between the first value and the second value for the electric flux between the second electrode and the object.

10. The method as claimed in claim 1 , wherein the first distance is different from the second distance, and the first potential value is equal to the second potential value.

11. The method as claimed in claim 1 , wherein the first distance is different from the second distance, and the first potential value is different from the second potential value.

Assignees

• Makuth Jens
• Scheibner Dirk
• Schimmer Jürgen
• Siemens Ag

Inventors

• Makuth Jens
• Scheibner Dirk
• Schimmer Jürgen

Classifications

• G01R19/0046 Primary

  characterised by a specific application or detail not covered by any other subgroup of G01R19/00 · CPC title

• G01R29/12 Primary

  Measuring electrostatic fields {or voltage-potential} · CPC title