Matsushita Electric Industrial Co., Ltd.

Koichi Takemura

Yukio Nagaoka

Osamu Eguchi

Shuji Ab

A flow meter measures a flow rate of fluid flowing through a flow passage based on a duration of propagation of an ultrasonic wave along the flow passage. A signal of the received ultrasonic wave is then compared with a reference voltage to detect an arrival of the ultrasonic wave. A voltage setting unit determines the reference voltage to an appropriate level according to a signal output from a propagation measuring unit which measures a duration of propagation of the ultrasonic wave along the flow passage from the start of transmission of the ultrasonic wave to the output of a signal from a judging unit as the reference voltage being changed. The reference voltage is determined readily and accurately, the flow meter measures the flow rate with the appropriate reference voltage.

Flow meter

A flow rate measuring apparatus includes: flow rate detection section and provided in a fluid flow path ; a measuring section for measuring an output from the flow rate detection sections and ; a cycle setting section for setting a measurement cycle of the flow rate detection sections and ; a resolution setting section for setting a measurement resolution of the measuring section ; a flow rate calculation section for calculating a flow rate based on an output from the measuring section ; and a measurement control section for controlling each of the sections.

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Nara, Japan

Koichi Takemura