A new mechano-optical technique to measure local velocities in opaque fluids

A novel technique has been developed to measure the local velocities in opa que liquid flows such as liquid metals. The measuring principle is based on the separation of a direct mechanical interaction between flow and sensor tip and the optical acquisition and processing of the sign;ll. In principle , this fact allows the extension of the range of applicability to higher te mperatures. Furthermore, the insensitivity of the system to electrical nois e and external magnetic fields can be considered as an important advantage. Until now, the sensor has been tested in metallic melts up to temperatures of about 350 degrees C. We present measurements of the local velocity obta ined in an eutectic InGaSn melt driven by a rotating magnetic field. (C) 20 00 Elsevier Science Ltd. All rights reserved.