Accuracy and interpretation of results from the DISA momentum flux meter

The momentum flux apparatus was tested for accuracy in vitro. Errors were within an acceptable range for clinical evaluation and research of meatal properties in male patients — provided the stream exit angle was horizontal within 10–15 degrees. Measurements from the apparatus give information about the rigid nozzle or distensible meatus from which the stream is discharged. It is stressed, that great caution has to be exercised in the interpretation of the residual kinetic energy density and of the energy loss during micturition.