Flow measuring device esp. for measuring flow of fuel in fuel injection system

摘要

The flow meter has an impeller (1) placed in a fluid flow path. The rotational speed of the impeller is measured using laser or ultrasonic waves. A transmitter (2) generates laser or ultrasonic waves at a fixed frequency. The laser or ultrasonic waves which are reflected by the end of the impeller are detected by a receiver (3). The difference in the frequencies of the received signal with respect to transmitted signal is fed to a data processor (9). The data processor calculates rotational speed of the impeller using this value.