Method for Operating an Electromagnetic Flowmeter and Electromagnetic Flowmeter

A method for operating an electromagnetic flowmeter having a measuring tube and a coil arrangement for generating a magnetic field at right angles to the direction of flow through the measuring tube, comprising:

• periodically varying the direction of the current flow through the coil arrangement;
• maintaining an electrical current flowing through the coil arrangement substantially constant;
• determining a voltage applied to the coil arrangement and/or its derivative;
• and
• comparing the determined voltage or voltage derivative with an allocated reference value.

An electromagnetic flowmeter, comprising:

• a measurement tube;
• a coil arrangement for generating a magnetic field at right angles to the direction of flow through the measuring tube, wherein the direction of the current flow through the coil arrangement is periodically varied and, within a period, following a rise to a predetermined value, the current is kept substantially constant;
• and
• a measuring device with which, with the coil current kept constant, the voltage applied to the coil arrangement and/or its derivative can be determined and that an evaluating device is configured such that the respective value determined is compared with an allocated reference value.