| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flow meter for accurately measuring the flow rate of fluid without using any temperature sensor. <P>SOLUTION: When the average cycle of vibration is calculated from the zero-cross point of the free vibration section Wb of a reception waveform W corresponding to water solution of a prescribed temperature, the average cycle depends on only a temperature, and the temperature is calculated. An ultrasonic beam is emitted from an upstream and a downstream to the water solution as fluid, and on the basis of the obtained reception waveform W, the flow speed of the water solution is calculated from a propagation time when it propagates in the water solution. This flow speed is temperature-corrected based on the temperature so that an accurate flow rate can be calculated. <P>COPYRIGHT: (C)2012,JPO&INPIT |
