Patent ID: 8548755
Filing Date: 2013-10-01
Classification: G01F

Abstract:
1. A flow rate measuring device comprising: a first transducer and a second transducer for transmitting and receiving an ultrasonic wave signal and being placed in a flow path inside which a fluid passing through; a timing part for measuring a propagation time of the ultrasonic wave signal transmitted between the first transducer and the second transducer; a timing controller for executing a unit measurement process, in which the timing part measures the propagation time of the ultrasonic wave signals in the forward direction from the first transducer to the second transducer and the reverse direction from the second transducer to the first transducer by switching a transmitting direction of the ultrasonic wave signal to the forward direction or the reverse direction; a time differential memory part for storing a time differential between the propagation time of the ultrasonic wave signals in the forward direction and the propagation time in the reverse direction measured every K times execution of the unit measurement process; a flow rate calculating part for calculating a flow rate of the fluid passing through inside the flow path based on a sum total of the propagation time in the forward direction and a sum total of the propagation time in the reverse direction obtained after at least K times execution of the unit measurement process; and an estimating part for estimating a change in the momentary flow rates of the fluid based on the time differentials obtained every K times execution of the unit measurement process and stored in the time differential memory part.