A flowmeter is a device used to measure the speed of water. This tool calculates water velocity by relating the number of revolutions measured at a given time interval. For meteorology and hydrometers, Molina with series of blades are more useful. Blade rollers are suitable for measuring high speeds. There is a linear relationship between the velocity of water (v) and the number of revolutions of the Molina axis (n), which is as follows:
V=a+bn
b: The hydraulic pitch of the flowmeter impeller (meters per round) obtained by the chariot test on the channel.
n: Impeller rotation (round per second)
a: Flowmeter constant (meters per second) obtained by the chariot movement test on the channel.