Method for generating a diagnostic from a deviation of a flow meter parameter

A method for detecting a deviation in a flow meter parameter of a Coriolis flow meter, comprising steps of:

• measuring a differential pressure across at least a portion of the Coriolis flow meter;
• determining an expected differential pressure based on a known fixed fluid viscosity;
• measuring a flow rate with the Coriolis flow meter;
• comparing the measured differential pressure to the expected differential pressure based on the measured flow rate;
• and
• detecting a deviation in the flow meter parameter if the difference between the measured differential pressure and the expected differential pressure falls outside of a predetermined threshold limit;
• wherein the deviation in the flow meter parameter indicates the presence of a coating in the Coriolis flow meter.