Method and apparatus for validating the accuracy of a flowmeter

A method and apparatus for testing sensors in a fluid flow conduit to verify the accuracy of the flowmeter of which the sensors are a part. Where two similar sensors are employed, active and reference sensor functions are interchanged to verify their functioning accuracy. Alternatively, different stimulation levels can be used to provide a basis for cross-correlation of sensor outputs. A single, or multiple, time-shared sensor can be employed in place of two sensors. Transient or steady state responses are employed. Many sensor types can be used.