Method for determining flow velocity of fluid loaded with particles, involves determining Doppler-frequency from difference of medium frequencies, and determining components of flow velocity of fluid from Doppler-frequency based on equation

摘要

The method involves regulating laser mid-band frequency based on compensation measuring method during measurement of electrical signals, such that an operating point for a measuring circuit (50) remains constant. Laser medium frequency of a reference radiation having no Doppler-frequency conversion is measured through evaluation of the radiation in a reference path (51) by a photodetector (44). Doppler-frequency is determined from the difference of medium frequencies, and components of flow velocity of the fluid are determined from the Doppler-frequency based on a specific equation. An independent claim is also included for a Doppler-global-velocimeter for determining of flow velocity of fluid.