Electromagnetic methods of turbulence measurements - shortcomings and advantages.

Two major electromagnetic methods of turbulence measurements are discussed. Both methods are based on the measurement of the electrical field induced by the fluid motion in the presence of a magnetic field. In the first method a multielectrode potential difference probe was used in the presence of an external magnetic field, while in the second one the source of the magnetic field was incorporated in the probe itself and the magnetic field was strongly localized around the probe. Shortcomings and advantages of both methods are discussed along with recent developments. (A)