variavel0=<b>Sonia Magalhães dos Santos</b> - vnsantos@mikrus.com.br FURG
<b>Jorge Alberto Almeida</b> - dfsjaa@furg.br FURG
<b>Leandro Jorge Carvalho</b> - leanjorcar@bol.com.br FURG
<b>Luciano Vaghetti de Oliveira</b> - lvaghetti@vetorialnet.com.br FURG
<b>Abstract.</b> The work discusses the study of a flow meter, of axial turbine type, through knowledge of their rotation. Two different systems to meter the rotation are used: a CCD video camera, which capture images at 1/30 seconds through a cylindrical acrylic transparent tube, which are load to microcomputer, or are processed ON-LINE, and a digital sensor which count how often one blade is observed, in a period of time. The study was held in a calibration rig for water flow meters which consists of a reservoir, a pump moving the water in closed circuit , tubes and a flow regulator.
<b>Keywords.</b> axial turbine, flow meter, digital image processing, signals processing.