| US 7,546,212 B2 | ||
| Method and device for operating a flow meter | ||
| Daniel Schrag, Zurich (Switzerland); Harald Grothey, Goettingen (Germany); Kai Hencken, Loerrach (Germany); and Markus Naegele, Bad Saeckingen (Germany) | ||
| Assigned to ABB AG, Mannheim (Germany) | ||
| Filed on Jul. 03, 2007, as Appl. No. 11/822,293. | ||
| Claims priority of application No. 10 2006 033 112 (DE), filed on Jul. 18, 2006. | ||
| Prior Publication US 2008/0016967 A1, Jan. 24, 2008 | ||
| Int. Cl. G01F 1/00 (2006.01) | ||
| U.S. Cl. 702—45 [73/861.12] | 16 Claims |
| 1. A method for operating a flow meter, the method comprising:
applying a first input signal in the form of a current or a voltage to a first electrode of the flow meter;
measuring a response signal at second electrode of the flow meter at which a second input signal is not applied;
determining impedance values at the second electrode based on the response signal;
comparing the determined impedance values of the second electrode with previous impedance values of the second electrode stored
in an evaluation unit; and
determining a status of deposit formation in a flowing medium of the flow meter based on a comparison result.
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