Monitoring the condition of a vibronic sensor

A method for monitoring a condition of a coil, wherein the coil is part of a device for determining at least one process variable of a medium in a container, the method comprising:

• applying an electrical excitation signal to the coil and receiving an electrical reception signal from the coil;
• determining a first value for the reception signal at a first predefinable measurement time;
• comparing the first value for the reception signal at the first measurement time with a reference value;
• and
• determining a condition indicator for the coil on the basis of the comparison determining a second value for the reception signal at a second predefinable measurement time;
• and
• determining a temperature of the medium based on the second value for the reception signal.

A device for determining and/or monitoring at least one process variable of a medium in a container, comprising:

• at least one coil,
• wherein the device is designed to implement a method for monitoring a condition of the at least one coil, the method including:
• applying an electrical excitation signal to the coil and receiving an electrical reception signal from the coil;
• determining a first value for the reception signal at a first predefinable measurement time, wherein the first predefinable measurement time is selected so that it is within a predefinable first time interval in which the reception signal reacts, in the form of a step response, to a sudden change in the excitation signal;
• comparing the first value for the reception signal at the first measurement time with a reference value;
• and
• determining a condition indicator for the coil on the basis of the comparison.

A method for monitoring a condition of a coil, wherein the coil is part of a device for determining at least one process variable of a medium in a container, the method comprising:

• applying an electrical excitation signal to the coil and receiving an electrical reception signal from the coil;
• determining a first value for the reception signal at a first predefinable measurement time;
• comparing the first value for the reception signal at the first measurement time with a reference value;
• determining a condition indicator for the coil on the basis of the comparison, wherein the condition indicator is a conclusion about a defective electrical contact or a cable break in the region of the coil or of at least two connection wires;
• and
• detecting a defective electrical contact or a cable break in the region of the coil on the basis of a deviation of the step response of the reception signal in reaction to the sudden change in the excitation signal from a reference jump response.