| abstract |
An electronic fluid flow meter (50) is disclosed which includes an LSI digital device (1), and an LSI analogue device (2). The digital device (1) drives a pair of acoustic transducers (5, 6) to transmit acoustic waves within a fluid, the flow of which is being measured. The acoustic waves are received within the analogue device (2), the moment of arrival being determined by envelope detection associated with the phase of the received signal. The reception of a signal stops a counter (23) within the digital device (1), the value in the counter (23) representing the time of flight of the acoustic signals within the fluid. Fluid flow data can be stored on an EEPROM (4) from which, meter data can be read using a liquid crystal display (7) or via an interface port (3) to an external device. |