ULTRASONIC FLOWMETER AND METHOD FOR ASSESSING RECEPTION STRENGTH RELIABILITY

To assess the reliability of reception strength quickly with high accuracy.SOLUTION: An ultrasonic flowmeter comprises: a propagation time measurement unit 16 for measuring the propagation time of an ultrasonic wave when measured in a forward direction by transmitting an ultrasonic wave from an ultrasonic transducer 11 and receiving it by an ultrasonic transducer 12 and the propagation time of an ultrasonic wave when measured in a reverse direction by transmitting an ultrasonic wave from the ultrasonic transducer 12 and receiving it by the ultrasonic transducer 11; a reception strength detection unit 19 for detecting reception strength in the forward direction on the basis of each ultrasonic wave reception signal when measured a prescribed number of times per given time in the forward direction, and detecting reception strength in the reverse direction on the basis of each ultrasonic wave reception signal when measured a prescribed number of times per given time in the reverse direction; and a reliability assessment unit 20 for assessing the reliability of reception signal on the basis of a difference between the reception strength in the forward direction and the reception strength in the reverse direction.SELECTED DRAWING: Figure 3 【課題】受信強度の信頼性を高精度かつ迅速に判定する。【解決手段】超音波流量計は、超音波振動子１１から超音波を送信して超音波振動子１２で受信する順方向の計測回のときの超音波の伝搬時間、および超音波振動子１２から超音波を送信して超音波振動子１１で受信する逆方向の計測回のときの超音波の伝搬時間を計測する伝搬時間計測部１６と、一定時間当たり所定回数の順方向の計測回の各超音波受信信号に基づいて順方向の受信強度を検出し、一定時間当たり所定回数の逆方向の計測回の各超音波受信信号に基づいて逆方向の受信強度を検出する受信強度検出部１９と、順方向の受信強度と逆方向の受信強度との差に基づいて受信強度の信頼性を判定する信頼性判定部２０を備える。【選択図】 図３