A method and apparatus are provided for calibrating a flow meter having an
array of sensors arranged in relation to a pipe that measures a flow rate
of a fluid flowing in the pipe. The method features the step of
calibrating the flow rate using a calibration correction function based
on one or more parameters that characterize either the array of sensors,
the pipe, the fluid flowing in the pipe, or some combination thereof. The
calibration correction function depends on either a ratio t/D of the pipe
wall thickness (t) and the pipe inner diameter (D); a ratio t/.lamda. of
the pipe wall thickness (t) and the eddie wavelength (.lamda.) of the
fluid; a Reynolds number (.rho.UD/.mu.) that characterizes the fluid flow
in the pipe; a ratio .DELTA.x/D of the sensor spacing (.DELTA.x) and the
pipe inner diameter (D); a ratio f.DELTA.x/U.sub.meas of usable
frequencies in relation to the sensor spacing (.DELTA.x) and the raw flow
rate (U.sub.meas); or some combination thereof. The apparatus takes the
form of a flow meter having a calibration correction function module
performing the aforementioned functionality.