| 摘要 |
PURPOSE:To enable to bring a correcting amount of zero even with no measuring device, by a method wherein an operation to bring a correcting amount of a correcting means to zero is performed through a switching operation of a switch. CONSTITUTION:When it is brought to a condition that a flow of fluid passing an oscillator for a flow meter can be shut off, a switch S11 is turned OFF, and a switch S12 is brought to ON in synchronism with the switch S11. If switched to said condition, when one transmitting and receiving device acts as a transmitter, a monostable multivibrator 31a provides a delay time, and when the transmitting and receiving device works as a transmitter, a monostable multivibrator 31b provides a delay time. Thus, the delay time of the multivibrator 31b is varied with a flow brought to a zero condition, a delay time against each transmitting and receiving device is relatively changed, and a regulation is made so that an output attains a 0, and this permits the correction of displacement in zero point of an oscillator for an ultrasonic flow meter. |
