METHOD AND APPARATUS TO DEFINE THE VELOCITY OF A FLOWING FLUID

摘要

To determine as precisely as possible the flow rate of a liquid flow inside a tube by means of minimal technical and especially minimal apparatus complexity the invention provides with a procedure and an apparatus to determine it. In this process the liquid is heated by means of an optical heating beam while the point of heating is shown through by an optical detection ray. The axis of the heating- and the detection beam coincide at least in the point of heating. The detection beam is absorbed via an array of detectors. In the apparatus the heating device which heats the interior area of a limited internal area of the liquid and the optical control unit of the laser beam are arranged that way that a measuring beam shines through the absolute heating point.