Abstract:
An apparatus (1) for calculating fluid flow in a channel, comprising a probe member (1) which detects fluid depth (L) in the channel; a mechanism (4) for measuring average fluid velocity in the channel; a mechanism for correcting the detected fluid depth based upon the measured average fluid velocity in order to account for drawdown; and a mechanism (2) for calculating average flow rate based upon the average fluid velocity measurement and the corrected fluid depth value.