Flow measuring device

摘要

A flow meter includes a flow path through which a fluid flows; a pair of transceivers for sending and receiving an ultrasonic wave propagating across the flow path; and a flow calculation section for calculating a flow rate of the fluid flowing through the flow path based on a result of the ultrasonic wave being sent and received by the pair of transceivers. The flow path has an equal flow speed area in which the fluid flows at a substantially equal flow speed over an entire flow rate area ranging from a high flow rate area to a low flow rate area. The pair of transceivers send and receive the ultrasonic wave so that the ultrasonic wave propagates in the equal flow speed area.